Dynamos/Generators and Regulators
A PDF article discussing Dynamos/Generators and Regulators faults and causes, types of oil pumps, and oil pump faults reprinted from Moss Motoring, Fall 2010 can be downloaded here.
Oil Pump Problems
A PDF article discussing lubrication faults and causes, types of oil pumps, and oil pump faults reprinted from Practical Classics, August 1982 can be downloaded here.
How they work and what to do if they don't. A PDF article reprinted from Practical Classics, August 1982 can be downloaded here.
YT hood folding
How to fold away your MG YT hood per the Supplement to the Workshop Manual
Gear lever spring replacement
I don't have a wireless fitted to my YB. Quite happy to be entertained by the hum and whirrings from the XPAG and general tyre/road generated noises. However, my peace was shattered by the hideous rattle of the gear lever. Fortunately, new springs are available and the fit is a simple job. Seats out, carpets up, gearbox cover removed four bolts on gear-lever cover and ready to replace. Fitting the spring is easy. Put spring in vice. Fit two professional quality cable ties to spring but do not put through small end of spring as it will not fit over end of lever. Once cable ties are in position, compress spring in vice and tighten each tie until spring is completely compressed. Put spring onto lever end. Fit washer and split pin. Remove cable ties. Job done!
PLC Switch - repairing
Click here to download notes on how to repair the PLC switch fitted to MG Y/Ts.
Tubular / Telescopic Shock absorbers brackets
If you are converting your suspension to tubular or telescopic shock absorbers, Tony Slattery has provided a drawing of his conversion brackets here.
Luvax Shock Absorber refurbishment
Extensive notes on how to refurbish your shock absorbers can be read here. See also Rebuilding Rear Shock on this page too.
Oil Pump - removal of
Drain the radiator and slack off the top and bottom water hoses.
Remove the front engine mounting bolts holding the engine bracket to the engine bracket to the rubber block. Slightly jack up the engine at the front. This allows the pump to clear the frame member.
Remove the oil pipe from the oil filter to the oil pump.
Remove the eight bolts securing the pump to the cylinder block.
Remove the pump by gently tapping the side of the pump body and withdrawing backwards. Screw a suitable extractor into the end of the driven gear shaft and withdraw from the cylinder block.
MG Car Company - Workshop Manual, UK - added because it is often thought necessary to remove the engine from the car in order to remove the oil pump.
Ancillary modern electrical devices, wiring them in
Keith Herkes had a query on the BBS Bulletin board about checking vehicle speed when travelling in France. I have had the same experience as the French police are pretty keen on precise speed limits. A small complication it that the continentals use kph instead of mph so it involves a little mental gymnastics to calculate accurate metric speed. (Seem to remember a similar deal when driving from Seattle to Vancouver British Columbia!). Not usually a problem with the Y Type unless you are going too slow!
My solution is quite simple as it uses a Garmin Sat Nav. The GPS speed reading is actually more accurate than the car speedo even with most modern cars. The two snags to overcome with fitting the GPS to a Y Type or any other older car is the lack of a power socket (cigar lighter) and the vehicle polarity. My answer is not very elegant, but it works OK. I have a short pigtail lead that I can attach directly to battery terminals that is fitted with a female connector socket. As long as the leads are colour coded red positive and black negative and the red lead goes to the centre terminal on plug, any polarity sensitive device can be used.
On the Y, the battery box is conveniently situated right next to the opening windscreen. It is a simple matter just to hook up the pigtail to the battery, fit the GPS adapter, and put lead under windscreen frame. when fitted there is about 6 inches of cable visible from back of bonnet to windscreen frame. Speed reading is shown full time and mph or kph can be selected as required.
I do not usually use the GPS function for journey planning as I prefer to plot my own routes especially in areas that I know quite well already. I attached some photos just to show installation. When not in use, the sat nav, wiring and suction bracket can be put in glove box or just removed from vehicle if required. The pigtail lead also works OK with 12v inspection/ lead lamps that are not polarity sensitive.
Mick Bath, UK
Trafficator switch overhaul
The combined switch on the MG Y Series Saloons consists of a Bakelite assembly containing the horn push and a clockwork operated ring to operate the trafficators. There are at least two basic types of switch and they a re similar in principle if not in exact detail.
Complete switch assembly with centre horn button and rotating ring for trafficators. To remove assembly from steering column, push column full forward and lock with half butterfly nut. Remove single attachment screw on steering wheel boss. Pull switch assembly off and remove four wires from switch (if necessary, mark wire positions). Prise chrome ring from boss to reveal spring and spacer. Do not attempt to undo brass screws holding horn contacts to boss. Tease top hat shaped spacer out of boss to reveal cheese headed screw.
Turn switch assembly over and remove paxoline circular shape with four screws. I have marked the screws for identification purposes.
Remove centre screw to release contact cam assembly (note spacer under cam).
Clockwork mechanism can be carefully removed to show timer cams and return spring. Spring can be replaced easily but patience is required as it is a bit fiddly!
Two screws connecting the horn contacts to hub. Short brass screw to earth on hub body, long brass screw connects horn pigtail wire to horn power supply using an insulated sleeve and fibre washer with a nut. Access to this nut and bolt is only after clockwork mechanism has been removed.
Clockwork mechanism can be carefully removed to show timer cams and return spring. Spring can be replaced easily but patience is required as it is a bit fiddly!
Further stripping of trafficator assembly shows spokes on moving outer switch and the pegs on the inner fixed hub of switch. ( have marked these with snopake just for reference). These must be lined up correctly or rotary outer part of switch will not move through full range.
Mick Bath, UK
Screw sizes for the trafficator control unit
The screw sizes for the trafficator control ring are as follows:
- The four wiring screws on the clockwork mechanism are 7/64” Whitworth – 48 threads per inch – 6mm long.
- The three screws that retain the clockwork into the horn mount are 5BA – 43 threads per inch – 8.5mm long.
- The single screw that retains the trafficator ring to the clockwork is 1/8” Whitworth – 40 threads per inch – 8mm long.
- The ground wire screw and nut that retains the horn contacts is 7/64” Whitworth – 48 threads per inch – 19mm long.
- The non- ground screw that retains the horn contact is 7/64” Whitworth – 48 threads per inch – 14mm long.
- The chrome countersunk screw that retains the centre in the steering whell is 2BA – 31.4 threads per inch – 13mm long.
Tony Slattery, Australia
Jackall Rams - repair of
Fellow Y owner, Malcolm Hickman and I embarked this week on a journey to restore the Jackall jacks on our respective cars — Malcolm's because his rear jacks were leaking, and mine because they were an unknown quantity and it's easier to restore them whilst undergoing the complete restoration of my car. Download a PDF file here.
Neil Wakeman, Australia
Front suspension spring compression
There are a variety of tools for compressing a coil spring to install it between two A arms. Relatively inexpensive tools with a threaded rod having movable hooks on each end are commonly seen. Some are designed to go inside the coil spring and some arc designed to hook on the outside. If you can get the tool in a convenient position it may work.
There are more expensive hydraulic and pneumatic tools that make it easier to compress the coil spring. These are used mostly by professionals who do a lot of undercar work. The cost of these tools may be excessive for the amateur who does this job very rarely.
A technique that we have used in our shop with repeated success is illustrated here. It requires a strong, ratchet style tow strap and a good floor jack. You can hook the tow strap onto the jack as shown here or you can slide it under the jack and wrap it completely around the jack and the suspension.
Seat the spring in its upper holder, then bring the A arm up to the bottom of the spring so that the lower spring seat will catch the bottom of the spring and hold it in position as the seat on the lower A arm is pushed upwards. then, raise the jack against the bottom of the A arm, making sure it is in a spot where it pushes squarely against the A arm. Sometimes a block of wood helps position the jack just right and protects the paint on the A arm.
The jack will not raise the frame of the vehicle because the straps are holding the frame to the jack. And the jack will not lift, because the arm with the jack pad on it is pushing against the frame and forcing the jack downwards.
Once you get the lower A frame raised to the right height, you can insert the long bolt that goes through the holes on the outer ends of the lower A frame. You may have to use a long screwdriver or a drift to line up the holes and tap the bolt slightly. Then, fasten everything up with all bushings and washers in place. Tighten the castle nut per shop manual instructions, slip a cotter pin through the "turrets" and remove the strap and jack.
We can't guarantee this works on all vehicles, but it has worked well for us at least a half dozen times on a variety of cars. As with any restoration job. go carefully, think things out, do a "dry run" to test the equipment and wear proper safety gear like gloves and a face shield. Also be safe and cautious at all times. It's no fun having an energized coil spring flying around a shop!
John Gunnell, USA - Originally published in Classic MG Magazine Issue #52 2013
Sun roof rattles
My YB is obviously getting bored, it is now dreaming up various means to keep me busy, but in such a fashion, the fault takes some quite involved detective work. The latest item to my tired old mind was another rattle, but really carefully hidden. A normal road speeds in quiet lanes on nice days... nothing. But on main roads, doing a nippy 55 mph, in windy conditions there was this odd clank rattle clonk. It was a very muted sound, and impossible to source because of the other various members of the YB's orchestra such as minor axle wine, busy engine, tyre noise, etc. Then one day, whilst parked by the busy and fast A5 trunk road, a 42 tonne lorry thundered past, with a trailer on. With no engine running in the YB, I heard that noise again. As luck would have it I was looking at the sun-roof. It lifted a little with the various pressure waves of the thundering juggernaut, as they passed over the YB. There was the noise, the panel was a little loose.
I pulled back the roof lining by the two front rail clips, to find the nearside one was indeed loose and the felt runner was worn. The clip is held by one screw, so it was a simple job to loosen it off move the clip in a fraction, because of slot provided for such adjustment. Once tight, the play had gone.
This also cured the tendency for the panel to run too close to the offside edge, marking the paint.
Neil Cairns, UK
Fixing the nailed in trim
Some of the trim in the MG Y Type was originally fixed into place by twist nails with the trim being nailed into rolls of very well twisted paper that formed a flexible rope. This was then able to be pushed into the curved channels in various places around the body tub. I have used twisted paper ribbon (available on line in many craft stores). Some of the trim in the MG Y Type was originally fixed into place by twist nails with the trim being nailed in to rolls of very well twisted paper that formed a flexible rope. This was then able to be pushed into the curved channels in various places around the body tub. I have used twisted paper ribbon (available on line in many craft stores for example here). Modern suppliers only seem to sell this in narrow widths but you can cut several lengths from a roll such as this one then clamp one end in a bench vice and wind up the pieces to twist a new rope. Before you let go, have a friend tape up both ends with tape! Twist nails are readily available from your hardware store too, but be careful about the length that you buy - I found the originals were in different lengths, most were 7/8" - too short and you may not get a good grip through the paper, too long and you may come through the outer skin of the body shell ... so check your depth!
Rock Von Dullen, USA
Condenser ... and how to replace it
Condensers rarely go bad, but when your original condenser fails this PDF file tells you how to replace the condenser that was soldered to the base plate.
Masaaki Sakaguichi, Japan
Locking fuel filler cap
For some time now I have wanted to fit a locking petrol cap to my YB but how....well there is a simple method that allows you to keep the original cap if not on the car then for refitting at a later date if you want to. What you do is get a Morris Minor petrol filler pipe - its a lot shorter than the Y type one but otherwise identical in width and construction. Once you realise that the filer neck is 'sweated on' (soldered basically) it can easily be removed by heating it with a blow torch or even on a gas stove. The filler neck on the Y is also fitted this way so you take the Y filler neck off and after cleaning the end of the Morris filler neck you sweat (solder) it back on to the Y filler pipe in the manner you would do with a plumbing repair. You then get [off eBay possibly] a locking cap (with an adaptor for the Morris Minor - you need that so make sure it comes with it) and fit it to the new filler neck - OK it does not look original but it works and in the event of the car turning over (heaven forbid) the petrol wont leak out and it saves anyone putting stuff in or taking petrol out of the tank. If you want the original petrol cap back you unsolder the Morris filler neck and solder the Y one back on. Not for purists I suspect but if you want to use the car regularly a useful fitment.
Dave Mullen, UK
Running Board rubber strips - fitting to channels
The best way to install the rubber strip into the running board is to slip them in towards the body shell then pry the outside into the channel with a putty knife, or something less sharp. First though, measure the proper length then use a bench grinder wheel to taper and round off the ends.
Will Boden, USA
Rocker assembly (Valve Train)
Noisy tappets may not only be due to loose valve tappets. Here is a write up on how to rebuild your rockers.
Neil Wakeman, Australia
Lock repair - doors and boot
Does your door or boot lock not turn? If not, it is probably seized up. Here is awrite up on how to get them working again.
Neil Wakeman, Australia
Brake Fluids - DOT 3, 4, 5 and 5.1
A PDF file compiled by Michael Long outlines the advantages and disadvantages of the various brake fluids available can be downloaded here.
Michael Long, UK
Electrics not working?
After 40 years sitting in boxes, a couple of my electrical components failed to function properly when removed from their long hibernation. The cause in some cases was very simple — surface corrosion!
Control box — power was not getting through to the 'accessories' that work only when the ignition is turned on — wipers, trafficators, etc. The cause? The clip that holds the accessories fuse linking A3 and A4 terminals on the control box had corroded and contact between the fuse end and the clip was lost. The solution? Clean them up with some emery paper. I also cleaned the fuse holder clips at A1 and A2, for good measure.
Dynamo — same deal. After pulling my non charging dynamo to bits and testing every part without finding a problem, my auto electrician mate concluded that necessary electrical contacts had been lost through corrosion. He cleaned and reassembled the unit without replacing anything, and it worked like a charm!
Wipers — these wouldn't work either because the points at the on-off switch were corroded. A quick clean with the emery paper and the problem was solved.
Fuel pump — similar but different. That would not work until I replaced the stiff diaphragm with a supple new diaphragm.
The moral of the story ... look for the simple solution before ripping things apart!
Neil Wakeman, Australia
Ever since the car has been on the road (1992) I have carried a few spares in the car because we have done a few trips across Australia and back and other long trips including the UK and Europe of course. These spares have lived in plastic ice cream containers in the spare wheel compartment which are now all out of shape and lids that don't fit so a little retirement project was to build my very own fit to shape "Louis Vuitton" cases to fit where original tools that I don't have and don't need would normally go. A little over the top perhaps but might give our Y Type brothers a thought for something they could make. Their odd shape was a challenge but for obvious reasons necessary. The curved section around the spare wheel I used a heavy plastic and the piece of aluminium angle located by the little bracket on the left and my home made spare wheel clamp is to keep the boxes in place.
Richard Prior, Australia
Auxiliary Dashboard and how to make one
I fitted an auxiliary dashboard to my Y to carry additional instruments and a plug in power point (for GPS etc.) Here are some notes on how I made it.
Michael Nicholson, UK
Boot and Spare Wheel Compartment seals
I have just about completed a rebuild of an MG Y/T and I was looking for a suitable seal to fit the lip around the boot (aka trunk) lid and Spare Wheel Compartment (SWC) opening. I decided a neoprene seal would be the best as it will not hold water when it gets wet. I emailed a couple of suppliers with my dimension requirements - about 16mm wide and 5mm high (5/8th inch wide by 1/5th inch high).
The best quotation I had back was from Woolies (I & H Woolstenholmes Ltd) in the UK and so I ordered 2 possible products and their Self-Adhesive Black Sponge product hit the nail right on the head. Their product is 300-16-5 and you will need a total of 5 meters as the boot lid is 92 inches (2.44 meters) around and the SWC is 72 inches (1.83 meters).
First you should run the seal all the way around the opening and DO NOT remove the backing paper. Overlap the end by about 1 - 2 inches, then cut it. This will allow for shrinkage and also save you having to fight the long snake! Start at the bottom and centre of each opening, and remove the backing only about 6 inches at a time as you work the seal back in and around the corners (I go anti-clockwise) around the opening. When you are done, just leave the overlap for a couple of hours (overnight?) so the neoprene shrinks back. Push the seal firmly onto the rear of the opening so that the self adhesive gets a good contact - clearly the surfaces should be clean and free from dust and dirt first!
This seal will give you a nice filler and seal all the way around without causing the lids to stand out unnecessarily proud.
Paul Barrow, Washington State, USA
Sometimes it helps to know how the world used to be to understand why things were done that way. The reversing light on a Y-Type only works when the sidelights are switched on, not when the ignition is switched on. This is because reversing lights were fitted in the 1940's and 50's to "upmarket" cars to assist the driver in reversing at night.
It was only in the 1960's, that reversing lights were expected on the average car and as a warning that the driver had selected reverse gear. So. it is worth remembering this if you wish to indicate you have selected reverse in daylight, switch on the sidelights first. You can of course modify the wiring to enable the reverse lights to work when the ignition is switched on, and this will be the subject of another Y-Hint & Tip to follow.
The Classic Workshop, Australia
Oil Leaks from the rear main seal
Years ago I was wondering why T series had more oil leaks than other British cars using the same type of rear seal especially after the engine was shut off., MGA, Austin Healeys had the same reverse screw thread scroll. Midgets had the same seal into the 1970's. Even American cars in the 40's used the same type of seal, but they all have their tube trimmed short so the oil drops out of the cap above the standing oil.
If you look at the drainage tube and see how high the oil in the pan is when the engine is off you will see that the tube stands in the oil. I feel that the run off from the rear main fills the tube and then runs out the trough by the crank. If you trim the tube it lets the oil drop off into the pan and not well up in the trough of the main cap up by the crank scroll. I usually leave it about 1 inch long, the main bearing cap has a big cast appendage on it. Basically you want the oil to drop out of the tube above the tray but well below the cork gasket.
This is practice that I have found to help reducing oil leakage out of the bell housing, maybe not 100% but every little bit helps.
Joe Curto, USA
Ignition Coil and Timing
Download a great article here from Enjoying MG magazine, on everything you need to know about the Coil Ignition system in your car and ignition timing. This article, although generic in nature covers almost all Pre 1981 MGs.
MG Owners Club, UK
Trunion and King Pin replacement
Download a great article here from Brian Cox on Trunion and King Pin replacement. This article was originally published in Practical Classics in June 1992.
Brian Cox, UK
Rear Crank case seal leaks
Another way to get oil loss is to fit the bell housing cover plate the wrong way round, with the slot on the wrong side. This creates a vacuum in the bellhousing and pulls the oil out of the engine through the rear main bearing and oil scroll. I know people who had big oil leaks from the bell housing, and who have completely stripped an engine to examine/replace the rear seal who only needed to reverse this plate. You can work it out. Looking forward, the clutch/flywheel rotates anticlockwise. As a result, so does all the air in the bellhousing - and rather quickly too. If the plate is fitted with the slot on the left, all this rotating air will be thrown out of the slot and a vacuum situation develops in the bell housing (sucking oil out from the rear main). It is acting in the same way as does the water pump. With the slot to the right, this does not happen and there is even a slight pressure build up in the bell housing to push oil back into the engine. Most of these plates do have the word TOP stamped into them so it should not be too difficult, but with some corroded plates it's hard or impossible to see.
Clive Sherriff, UK
Fitting Flashing Turn Signals with Trafficators
Safety is something not to be compromised and many enthusiasts would like to have both the option of flashing indicators and the traditional semaphore arm signals operating on their car from the original steering wheel turn switch. Modern flashing indicators add a safety feature for the modern motorist who is not expecting to see (nor indeed are they looking for) a small arm on the middle and side of the car to pop out. The trafficators clunking in and out will satisfy the enthusiast both aesthetically and from the recreation of that 1950s driving experience!
There may be local requirements to fit internal repeater flashers, you will need to check this with your local Department of Transport (or equivalent) Office regulations. Also, some countries require that an audible device and an illuminating warning light must be fitted to a vehicle fitted with flashing turn signals. It would not be a major alteration though to run wires back inside the cockpit, via a correctly valued and orientated diodes (one way current passing switches) for both the left and right flashing indicator wires, to a suitably mounted repeater if this is the case.
In order to operate the Trafficators and the indicators concurrently with flashing turn signals, you will need to acquire two of the Lucas Flasher units (FL5 or similar) that were fitted to most British cars of the 1960s and 1970s. These can be easily mounted on lower bulkhead where the terminal connecting unit is located. The Steering Column slip ring has four terminals, one for the horn, one for the current feed and one for each trafficator. Both of the trafficators wires are green, the left one with has a white tracer and the right one with has a red tracer.
Take a feed from each of these trafficator terminals to each of the flasher units. The flasher units have three terminals and one will be redundant on each. Then take a feed from one side of the flasher unit to each pair (front and rear) of the indicators. The trafficators can then be operated at the same time as the indicator units, using the same trafficator switch on the steering column.
If you have not already done so, twin filament bulb holder conversions are available for the Lucas 1130 sidelights from suppliers such as Staffordshire Vehicle Components. These enable you to operate sidelights and indicators concurrently. However, orange indicator units are recommended for the rear of the car.
A circuit diagram together with a printed set of these notes can be downloaded here. Although this is based on the RF.95/2 Control Unit, the wiring suggestion can be fitted to any Y Type irrespective of the Control Unit type fitted.
Tony Slattery, Australia
Higher ratio rear differential
I opted to do a complete axle changeover - so you will need to find a spare Y-Type diff housing as well as a Morris Minor Diff Centre - I used a 9/41 (1:4.55) ratio. Ask other Y-Owners, someone close to you will have a spare housing.
All the work was done by a fellow Y-Typer and excellent engineer - Dick Pakeman at Helidon, Queensland. He makes rims for vintage & veteran cars as well a general engineering and vintage engine work. I got him to do 2 differentials for me and the total cost was $1500 which included new bearings/seals in the 2 differential centres, so $750 each. I supplied the MM differential centres, and 2 complete Y-Type housings. I thought it expensive at the time, but when you consider what he did for the money, it was very good value.
Attached you will find the analysis I did on engine RPM, tyre size and speed prior to the conversions. So here is how a "Brooklands Y-Type" differential is created:-
1) The sun gears are removed from the Y-Type differential centre and fitted to the MM differential centre - this allows you to use original Y-Type axles shafts. The MM front flange is OK as I recall and fits the Y prop shaft.
2) The mounting ring needs to be cut out of the Y-Type Banjo housing and a new ring made with the bolt pattern for the MM centre.
3) The new ring is welded in the correct location to suit the MM centre - there is about 6mm difference between the mounting flange and the axle line between Y & MM differential centres. This is most important to avoid broken axle shafts as you can well imagine.
4) Keep all the Y-bits, just in case a future owner wants to put back the Y-Type differential centre - just compare the pinion sizes between MM & Y.
5) You should then check the banjo is still straight after the new mounting ring is welded in - this can be done with a full width dummy axle and a press to correct any bend discovered - one of mine was bent forwards, the other backwards so I suspect the manufacturing tolerances in the late 40's were not that good.
6) Now its just a simple swap of the complete housing to the car and fitting the axles and brakes.
7) I use limited slip diff oil in all my cars at the recommendation of a differential specialist many years ago - it has much better wear protection and heat tolerance - nice and sticky too.
I fitted one of the "Brooklands" differentials to the YT in January 2009, before driving it to Geelong for the Easter National Meet, the car was driven to the top of Mount Buffalo on the Pre-War MG Week-end in October 2009 with ease, so the ratio is still OK for climbing steep hills with the 4:55 ratio. I then drove it from Melbourne to Adelaide for the 2010 National Meeting - doing the trip in 9 hours - then back to Melbourne before the trip to Canberra and then eventually back to Brisbane. The car broke down 9 times between Newcastle and Brisbane on the final leg, but with determination I got there. Just a couple of simple problems, but difficult to diagnose on the side of the road without the right gear. None of the problems were related to the "Brooklands Differential".
The trailer I was towing with the YT weighs 250kg and it had 212kg of tools, wheels, spares an cleaning equipment inside. The car was carrying me and luggage - total 145kg - and another 100kg for Deb and her luggage from Melbourne to Canberra. A YT weighs about 930kg - so all up 1,637kg powered by 1250cc and can cruise at 100km/h doing 3625 RPM.
Dick had previously fitted a MM differential centre to his Y, but made himself new axles to fit in the MM sun gears - he never thought the sun gears could be swapped until I suggested we try my idea. He also fitted a 5 speed gearbox with a bell housing he built himself.
MG Y-TYPE - ALTERNATIVE REAR AXLE RATIOS
|Bias Ply||Radial Ply||Radial Ply||Radial Ply||Radial Ply||Radial Ply||Radial Ply||Radial Ply||Radial Ply||Radial Ply||Input:|
|16" x 3"||16" x 3"||16" x 3"||16" x 3"||16" x 5"||16" x 5"||16" x 5"||16" x 5"||16" x 5"||16" x 3"||Rim size|
|36||36||41||38||38||41||39||41||36||36||# teeth crown wheel|
|7||7||9||9||9||9||8||8||7||7||# teeth pinion|
|6||6||6||6||6||6||6||6||6||6||3rd motion shaft|
|15||15||15||15||15||15||15||15||15||15||Take off pinions|
|1600||1600||1600||1600||1600||1600||1600||1600||1600||1600||Speedo fitted (revs/mile)|
|1||1||1||1||1||1||1||1||1||1||Top Gear Ratio :1 (4th)|
|2.06||2.04||2.04||2.04||2.095||2.095||2.095||2.095||2.095||2.09||Rolling Circumference (m)|
|781.2||788.9||788.9||788.9||768.2||768.2||768.2||768.2||768.2||770.0||Wheel turns per mile|
|1607.1||1622.9||1437.5||1332.4||1297.4||1399.8||1498.0||1574.8||1580.3||1584.0||Speedo turns per mile|
|14.9||14.8||16.7||18.0||18.5||17.1||16.0||15.2||15.2||15.2||MPH per 1,000 rpm|
|1664||1681||1489||1380||1344||1450||1551||1631||1637||1640||RPM @ 40 km/h (in top)|
|2497||2521||2233||2070||2015||2174||2327||2446||2455||2461||RPM @ 60 km/h (in top)|
|3329||3361||2977||2760||2687||2899||3103||3262||3273||3281||RPM @ 80 km/h (in top)|
|4161||4202||3722||3450||3359||3624||3878||4077||4091||4101||RPM @ 100 km/h (in top)|
|4577||4622||4094||3794||3695||3987||4266||4485||4501||4511||RPM @ 110 km/h (in top)|
|4781||4828||4277||3964||3860||4164||4456||4685||4701||4713||RPM @ 71.4 mph (in top)|
|0||1||-10||-17||-19||-13||-6||-2||-1||-1||% speedo error|
|NB -ve means reads slow|
|BREAKERS YARD SEARCH LIST|
|Teeth||Diff ratio||Standard fitment on:|
|11/41||3.727||Riley 1.5, Morris Major & Austin Lancer (Series 1 only)|
|10/39||3.9||MG Midget 1275cc (UK built cars), Mk1& Mk2 & Mk3 Sprites|
|9/38||4.222||MG Midget 1275cc (Australian built cars)|
|9/41||4.555||Morris Minor 1000 (PRE-1956)|
|8/39||4.875||Austin A30/Morris Minor Ute & Van|
|8/41||5.125||MG TB & TC, Morris Minor 1000 Vans & some Austin A30|
|8/43||5.375|| Austin A30 Ute, Morris Minor Ute, (in 803cc models)|
Download as tables as a PDF here.
Tony Slattery, Australia
Heat shield - fitting to a YT
This PDF file was written a while ago by David Pelham and Paul Barrow. If you need to fit a Heat Shield to a YT or twin carburettor saloon it will be of interest to you. This will help prevent "vapour lock" and fuel starvation issues caused by heat transfer from the exhaust manifold evaporating the petrol before it can get into the engine from the carburettors through the inlet manifold.
David Pelham and Paul Barrow, UK and USA
Rebuilding Rear Shock Absorbers/Dampers
Andrew Sorouni has provided detailed notes here of how to rebuild the rear shock absorbers. See this document for how to do this.
Andrew Sorouni, Australia
We all have stories of driving in the rain ... and arriving with a wet lap. Many times this is correctly blamed on the big, external seal that goes around the outside of the chrome surround. However, when I was driving my Y recently I happened to notice a bead of water forming on the inside above the chrome surround. I watched (while paying attention to the road too) as this swelled ... and then fell onto my leg. The source of the water ingress was not the outer seal of the windscreen but a failure of the inner surround seal. See this document for a cure for this!
Paul Barrow, USA
A document demystifying Antifreeze can be downloaded here.
Mike Long, UK
Emergency Fuel Pump
A document detailing how to make an Emergency Fuel Pump downloaded here.
Steve Locke, USA
Window winder mechanism replacement — front
Have you ever had that sinking feeling? Well I did on my way home from the Speckled Hen Run recently. "Wind the window up please dear" my wife Doreen said as we headed back to Radley College for our cream tea. Just as it got to the top "BANG" and it disappeared into the door. The winder went all easy to turn so I guessed something broke, or slipped off. I had no idea at the time how it worked, never having had a YA to bits. All my experience with building and fiddling with MGs has been with MMM and T types. Oh well, another job to do.
When I got home I took off the door panel and immediately saw what had happened and what a simple and ingenious system.
A very simple gear and chain driving a Bowden cable over some pulleys. For those who have never had the door panel off, the photo shows you what you will see. Looking at the diagram the winding handle connects to a gear over which passes a chain. A closed loop of Bowden cable is connected to each end of the chain with a loop and crimped ferrule. The system works thus:- Winding the handle anticlockwise pulls the left hand cable downwards. It passes over the first pulley "F" and passes through a clamp, which attaches it to the bottom of the window thus the window is raised. In order to lift the window evenly the cable then passed under another pulley "A" , down low in the door and up again over a second pulley "F" and down through another clamp attaching to the window. Hence both sides are lifted evenly. The cable then goes down and round the second pulley "A" and attaches to the other end of the chain. This ensures that the window is pulled down. The cable needs to be free of slackness to prevent the chain slipping on the gear. For this reason the two lower pullets "A" are adjustable.
Repairing the cable
When I examined the cable I found that it had broken where it is attached to the chain. The first action was to contact my usual supplier for a spare but unfortunately to no avail. I contacted David Pelham and he passed on my message to Paul Barrow, who gave me some useful information. The cable diameter is 0.072" (this confirmed that mine were correct also) and 76" (193.04cm) long. This gave me the minimum length I needed to order.
However, scanning via the web for Bowden cable I did find a supplier "Clark Engineering Supplies" and bought a coil (I have some spare if anyone should need some). As for the crimped ferrules I couldn't find any easily on the internet so I went to my local bike shop.
They couldn't provide anything suitable but one guy told me that he used to used a suitably sized insert from the plastic electrical connector blocks. Once the plastic is removed they can be used to solve the problem. Making the new winder cable was made very much easier using these as you can alter the length easily if you find it doesn't quite fit.
There is some adjustment in the two lower rollers, marked "A" in the diagram. I made the whole continuous loop, including chain, before I put it into the door. You will need to take out the bolt that secures the bottom of the window runner at the front edge of the door to be able to pass the cable down to where the gear wheel is. Other than that it is just a matter of fitting the cable into the pulley grooves and the chain onto the gear wheel. You will need to leave the clamp bars off the two positions where the cable is secured to the bottom of the glass before you start.
It pays also to slacken off the two lower pulleys where the adjustment exists. Easier said than done though. I found it helpful to remover the wooden window surround and the felt wiper bar from the door so that I could see the pulleys. It did require a little patience and tenacity though. Once in position and reasonably tensioned you can then position the window and put on the clamps. Some adjustment will be required to make sure that the window winds right up and fully down and is lined up at the top when in the up position. One done and everything works it's just a matter of putting all the other bits back again. Job Done.
John Harris, UK
Sump Tank or Drip Trap
I have just seen an advert for a sump tank in the Octagon Magazine at £55 and wondered if members would be interested in a couple of drawing I made for a tank and also a method of emptying the tank without having to jack up the car. At last years Spring Run a couple of people were interested and took some pictures of it. A sheet metal fabricator should easily be able to make one and at probably a lot less cost.
Below are my original plans and a modification suggested by Mike Long. David Pelham has now manufactured these and has has them available - check out his page here.
Original plans in PDF format
Modified plans in PDF format
Roy Clapham, UK
Drooping door handles
By the repeated effects of grinding (turning the handle with no fresh grease between the 2 parts) and pounding (each time the latch springs back upon slamming the door shut) the rotating soft steel part develops a flat spot upon its arc.
Gilles Backand, Canada
Penetrating (Releasing) Oil
For those who do like to do the work themselves and want to use the best and cheapest materials ... Penetrating (Releasing) Oil.
Tony's Y-Magic Penetrating (Releasing) Oil
75% Diesel Fuel
20% Mentholated Spirit
5 % Light machine oil (sewing machine oil)
I have used this recipe for working on my own cars for over 25 years. They were given to me by an old bush mechanic who estored tractors and farm machinery as well as the occasional Veteran Car
Tony Slattery, Brisbane, Australia
For those who do like to do the work themselves and want to use the best and cheapest materials ... a rust preventative solution.
Tony's Y-Magic Rust Preventative
25% Diesel Fuel
I have used this recipe for working on my own cars for over 25 years. They were given to me by an old bush mechanic who restored tractors and farm machinery as well as the occasional Veteran Car
Tony Slattery, Brisbane, Australia
Tachometer gear reduction drive - securing it!
I made mine out of a scrap piece of brass....very simple, a hole in one end for the grease fitting and then trap it under the brush cover. Some folks put a hole in the other end and connect it under one of the dynamo's through bolts: that seemed overkill to me. I replaced the greaser with a 2BA screw to get a better bite on it too.
Terry Sanders, California, USA
Veneering or Ironing away with a smoothing dash!
Also featured in our Reprinted Articles page, this excellent article by David Hague explains the technique for veneering your dash board. Originally printed in Safety Fast, June 1997.
Seat bolt gaps
I refitted the front seats on my MG YB following a super rebuild of the seats (mostly original leather, with a replacement panel virtually undetectable from the original). I found that it was not easy to judge how much to set the protrusion of the circular headed bolts which slide within the sliders for seat adjustment. Too little and the seat won't slide, or maybe not even fit into the slider. Too much and a seat will 'shake around'. Once a seat is in position the bolts cannot be adjusted due to the circular heads rotating within the sliders. So it was 'seat in', 'seat out' a number of times. (Maybe the factory used a gauge, but even that would not be meaningful today with years of use possibly distorting the sliders.) Then a simple solution dawned on me, and with a hacksaw cut in the threaded end of a bolt a screwdriver can be used to prevent a bolt rotating as the nut is adjusted with a spanner. Like most things, easy when you know how! (Webmaster's note: Apparently original seat bolts were made with slots in. They must have thought about that at the factory in the design stage too!)
Grommet over rear propeller shaft UJ
Replacing the grommet over the rear propeller shaft UJ if it has been lost has been difficult in the past due to it's large size (2 17⁄64 inch internal diameter). However, the grommet from the gearbox extension of an ADO 16 (Austin 1100/1300) is approximately the same size. The Original Equipment part number for this is 22A271, and it is described as Cover-dust-remote control housing. They can be obtained from most good ADO 16 suppliers.
Camshaft - size determination
Two different camshafts were supplied as original equipment for the XPAG and XPEG engines. The earliest type, part number AAA5776 (earlier numbers MG862/171 or X24084), was used in all TB and TC engines, and in TD engines up to engine number XPAG/TD2/24l15. This early cam requires a valve clearance of 0.019 in. The later type, part number AAA3096 (earlier number 168553) was used in all later TD and TF engines and requires a valve clearance of 0.012 in.
Unfortunately, now that even the newest TF is almost 40 years old, the engine numbers quoted above are not necessarily a valid guide for purpose of camshaft identification. Engines originally equipped with AAA5776 may have been fitted with AAA3096 in the course of an overhaul.
With the engine cold, remove the rocker cover and turn the engine over with the crank until #1 intake valve (2nd valve from front of engine) is wide open. At this point, #4 intake valve (7th from front) will be fully closed and on the exact center of the heel of the cam lobe. Set #4 intake to 0.021 in. clearance. This is the correct checking clearance for both cams, regardless of whether you use the degree wheel and dial indicator method or the simplified method which follows.
Now, wipe all the accumulated gook off the crankshaft pulley, and get out your measuring tape and a piece of chalk. Measuring around the rim of the pulley. make one chalk mark between 1⁄32 in. and 3⁄64 in. to the right (as seen from the front) of the top dead centre mark on the pulley. This corresponds to 5° BTDC, which is when the intake opens on the later cam (AAA3096). Make a second chalk mark 23⁄64 in. to the right of the TDC mark. This corresponds to 11° BTDC, which is when the intake opens on the earlier cam (AAA5776).
Next, turn the engine over with the crank (it's easier with the spark plugs out) until the pushrod for #4 intake valve just barely locks up enough so that you can't spin it between your fingers. At this point, the timing pointer on the timing chain cover should be more or less aligned with one or the other of the chalk marks.
If the pointer aligns with the 11° mark, then you have the early cam (AAA5776) and you should set the valve clearance to 0.019 in. with the engine hot. If the pointer aligns with the 5° mark then you have the later cam (AAA3096) and you should set the valve clearance to 0.012 in. hot. If the pointer does not align with either mark, go back through the entire procedure again to make sure you did it right.
What effect does the wrong valve clearance setting have on the engine? This is a bit difficult for the novice to pinpoint unless he can compare performance to a properly set up car. In general, however, an engine equipped with AAA5776, but with the valve clearance set at 0.012 in. will be very low on power. An engine equipped with AAA3096, but with the clearance met at 0.019 in. will be slightly down on power and will produce a really awful amount of valve clatter. You should also bear in mind the fact that while clearance which is too large is noisy, it doesn't necessarily produce any mechanical damage. On the other hand, burnt exhaust valves will almost surely result from unduly small valve clearance, as in the case of an AAA5776 cam set at 0.012 in.
Toolbox in the battery box
If you have replaced your old rather large battery with a "Mini" battery then you will have created valuable extra space in the battery box so why not use it for a tool tray. The drawing and photos show how a double tray fits in well, slides in and out and can be accessed from both sides of the engine compartment.
Mine is constructed of MDF with the joints being glued and screwed. It would help if you have the use of a table saw but sharp hand tools will do the job. The drawing gives most dimensions but basically you need to make a tray to fit inside the rim of the battery box and then glue a frame around it to support it on the top edge. Next make another tray to fit inside the frame. My dimensions will allow the trays to be lifted and removed without fouling the bonnet ridge.
Indicator / turn signals conversion (rear of car)
Stafford Vehicle Components provide LED flashers that can be discretely mounted inside the rear window too. SVC Part number 6416.
Murray Grainger, Australia
Indicator / turn signals conversion (front of car)
Stafford Vehicle Components now manufacture a kit to convert your white flashing torpedo side light to an amber one. It has two bulbs in place of the usual double filament single bulb. the flasher bulb being amber in colour.
I have always felt the white flashing side lights to be inadequate so when I saw this I thought it was a really good idea. I have just finished fitting mine and they work fine, a slight increase in the flash rate has resulted.
- The flash rate is a little faster but well within limits
- The side light is not quite so bright
- In the dark you can see a slight fade to white at the top but it is predominately amber
- The front screw needs extra washers when fitting to avoid it touching the bulb.
- I had to replace the fitted bayonets as they were not compatible with mine.
Peter Vielvoye, UK
Chassis number - where to find it
Every Y chassis number was manually stamped into the front left chassis leg, just forward of the hole for the steering rack. Over the years this will have been covered over with shellac, under-seal, grease and road dirt. With careful use of a heat gun, a broad knife, and a wire brush, this can be scrapped off to reveal the chassis number of your car. So, if you have lost your plate on the battery box, or suspect that your Y may be a hybrid of two cars, here is where to look for the number.
Oil Pressure, generating it after an engine rebuilds
After rebuilding the engine, the oil pump will need priming. This was a perennial problem with these 'Morris' pumps: they are high above the oil level. Depending upon the pump and year of the engine, you might have a priming plug fitted (see manual) where you can fill up the pump. Once full, wind away on the starting handle with the plugs out until you get oil coming up out of the rocker feed pipe, (disconnect this at the oil pressure gauge connection.) Once you get oil, reconnect and start the engine.
If you are unlucky and have no priming plug, you will have to 'fill' the pump by another means, possibly by using the oil feed to the filter pipe. I always pack the gears* on these pumps with Vaseline on assembly, and DO NOT TURN IT until the engine is ready to turn on the handle. The pumps gears soon shift the Vaseline, and pull up the oil from the sump. Again, I use the oil pressure gauge connection to check the oil is getting into the engine. *Do not pack the void that the gears are in - just the gears themselves so that the peaks of the cogs are covered. If you over pack the void you will risk clogging the feed from the sump strainer pan and also the pipes over to the Oil filter and galleries and not be able to pull any oil up from the sump as a result.
Today, pumps 'self-prime', but not so in the 1930s-40s. You will still need a few goes at it until the oil flows. Use the starting handle, do not run it until you know the oil is in the crankshaft gallery, (where the oil pressure gauge connection is.) Put plenty of oil in, as you now probably have an air-lock in the pipe to the oil strainer in the sump. You can try 'sucking' the oil up with a tube over the hole, but you need very good lungs for that!
Neil Cairns, UK
Fuel sender and gauge testing
The following is based on, and contains excerpts from, a tech article written by Mike Ash and Dave Smith for the MGA Register. These tests and procedures are the same for most cars that use the "FT" style Smiths sending units with an internal winding and die cast aluminium base.
To perform these tests, you may need to drain the fuel tank before removing the sending unit from the tank. Remember that gasoline is a highly flammable liquid, and that the vapor in a gas tank is a highly explosive gas. Be very careful to keep open flames away, and not to do anything that could create a spark near the tank.
The gas gauge system can be baffling to diagnose and repair — especially considering that a poor ground (at the tank unit or at the gauge,) a frayed wire, or "gremlins" could be the cause. This test procedure has been developed by using information contained in the Jaguar Factory Manual and information provided by Nisonger Company. The test requires a volt/ohm multimeter.
Testing the Fuel Tank Sending Unit
To test the sending unit with your multimeter on Ω x 10, the unit should show approximately 1 ohm with the arm down (fuel tank empty) and approximately 9 ohms with the arm up (fuel tank full). If there is too much less than 1 ohm, there is risk of damaging the fuel gauge coils. Zero ohms, which indicates a direct short, for even a few seconds, could burn out the coils.
Testing the Dash Mounted Fuel Gauge
To test the gauge, remove the gauge from the dashboard, taking care to mark the wires for reattachment. (The terminals on the back of the gauge are marked "T" for connection to the Tank unit, and "B" for connection to the Battery via the ignition switch.) Test the wire that goes from the gauge to the tank sending unit with a multimeter meter (on the Ω x 10 range). There should be virtually no resistance (zero Ohms). The wire must be unattached at both ends for this test. If the wire is open, or has more than 2-3 ohm resistance, replace as needed. The Gauge is designed to operate with an upper coil and a lower coil. It is the balance between these coils that moves the fuel indicator needle. The coils must be tested separately. Do not test for more than one second.
Test the top coil by giving 12 volts for a split second to the B-terminal while the gauge body is grounded. The "T" terminal should be left open. If the needle swings to FULL, the top coil is working correctly.
Test the bottom coil by giving a short burst of 12 volts to the B-terminal while both the gauge body and "T" terminal are grounded. If your gauge is working properly, the bottom coil will overcome the top coil and the needle will swing to EMPTY. To reiterate: Do not run either test for more than one second.
Identify your problem before buying a replacement tank sending unit or fuel gauge — or for that matter, any replacement part. You could spend a lot of money, wind up burning out the new replacements, and even make the situation worse. Think of it as replacing a fuse. If you do not figure out why the fuse blew in the first place and fix the problem, and instead simply keep replacing fuses, all you will do is waste time and money as each replacement fuse blows as well.
To get this hint as a PDF file - click here.
Engine Reassembly Torque settings and Checklist
Taking an engine apart is easy - putting it back together correctly and ensuring that you have checked everything is harder.Click here for a quick check list of torque settings and checks to be carried out on rebuilding an XPAG engine.
Dave DuBois, USA
Dash pots - which way round?
When you remove a carburettor dash pot, it is important to remember which way round it came off, and for those with twin carburettors, whether it was a front or rear one. Incorrect fitting may lead to the piston binding in the chamber. I made a small stand so that it is easy to remember which way to refit them.
Tony Slattery, Australia
Steering rack gaiters
When fitting new gaiters to your Steering Rack secure the ends with Cable Ties. It's much quicker, doesn't require you to skin your knuckles and if you ever need to change them they can be removed more easily than the normal rusted clamps.
David Pelham, UK
Carburettor float chamber - float fork drop
One of the causes of float bowl overflow, especially if the car has set for a long enough period that all of the gas has evaporated out of the float bowl, is, what is called excess float drop in today's lexicon. What this means is that the float or, in case of the H2 carburettors found in our cars, the float lever drops so far down that it traps the needle from the needle valve against the straight section of the fork and jams everything together so that the fork cannot raise to push the needle against it's seat to shut off gas flow (Note: This only happens when needle valves are used to shut off gas flow, regardless of make of the valve. It will not happen when Gross Jets are used in place of a needle valve). The permanent fix for this situation is to cut slots on either side of the straight section of the fork, next to the mounting holes. These slots (some forks come with the slots already cut) form a tab that can be bent down to limit the amount the fork will drop to the point where the needle valve will open but the needle will not become jammed and cause the float bowl to overflow (please ignore the Gross Jet that is installed in place of the standard needle valve, this is the only float bowl lid that I had to photograph).
Cut and bend
Adjusting tab and stop peg
Dave DuBois, USA
Heater - increasing its efficiency
Having recently fitted a Smiths Heater, I have today had my first YT run with a very efficient heater blasting me with hot air. This is I am sure is mainly due to Neil Cairn's tip in 'Y' Sheet 4 XPAG Engines on replacing the thermostat and blanking off the bypass hose. The heater warms up really quickly and gives out an excellent flow of hot air even in this cold weather.
Peter Vielvoye and Neil Cairns, UK
Carpet Strips - YT
If you have a YT and a set of YA/YB carpet strips you can shorten the rear on by 5 inches and hey presto you have a set of YT ones. (East Grinstead Small Works Team - making parts for MG Y Types)
Boot hinges - checking the handing
When refitting the boot hinges on an MG Y Type, care needs to be exercised as these are handed. That is to say the left hand hinge will only go on the left hand side of the car and the right hand one on the right hand side. The best way to identify which hinge fits which side is to temporarily hold the bottom hinge, or fit it, to the car body - not to the boot lid. By doing this and positioning the hinge in the open position, it should then be more apparent if you've got it correct. If you have the correct hinge on the correct side, the fit will be snug, if not there will be an unsightly gap at one side of the hinge where it does not touch the bodywork. Do not over tighten the studs when fitting either as they are brittle and snap easily.
A couple of years ago, I rebuilt a worn-out distributor for my Y Type using parts supplied mail order by Peter Roe, Northwest Classic Spares. He has the old Lucas data sheets and was able to supply all the correct parts including baseplate, cam, bob weights, springs, condenser, rotor arm, cap and the 407050 points. He's very helpful, and provides quick service at keen prices. His website is www.northwestclassic.co.uk and via email here.). Usual disclaimer - I've no connection with Peter or his business, other than as a satisfied customer.
Bill Bennet, UK
Brake cylinders - YB Front
When replacing YB front brake wheel cylinders either with new or overhauled one's it is possible to mount the cylinders incorrectly. That is upside down/wrong way around and it still look right. There is no help in the Overhaul Manual indeed it says they are interchangeable. However if you did as I did and on one side mount them wrongly then the result is the car pulling to one side which is why you did the job in the first place.
The Cylinders should have their horizontal centrelines in line with the centreline of the stub axle.(one with it's shoe up and one down of course). If they are wrong one cylinder will be above and one below the stub axle centreline. All still goes together but a graceful curved braking is obtained!
I always lay parts down as they came off before proceeding but his time they were disturbed. Only when both hubs were taken off and comparisons made did the problem reveal itself.
Ted Gardner, UK
When reading the Bulletin Board threads I've noticed there is some difficulty relating the SAE (Society of Automotive Engineers) oil viscosity requirements for our old cars to oils which are currently available outside the U.S.A. Perhaps it would be easier if the relationship between SAE and ISO (International Standards Organization) classifications were known. This chart show that relationship, plus the AGMA (American Gear Manufacturer's Association) grades for gear oils.
Example: SAE 140 gear oil is required for a differential unit. Cross to ISO 460. If a SAE 90 is required, use ISO 220 oil. If a 90W-140 is called for, ISO 320 might be correct for the application. Note how SAE Crankcase oil classifications are in a different band than the SAE gear oils. An SAE 10W-30 would be an ISO 32-100. W in SAE nomenclature stands for 'Winter'.
Scott Barrow, USA
The MG Y Fuel tank is an almost regularly shaped cubic rectangular design with straight walls. This makes reading the fuel gauge easy and eliminates guess-work. To avoid fuel blowing back (or 'the burp') when filling up the following guide may be helpful.
To Fill up
Paul Barrow, USA
The brake nipples are 11⁄32 inch A/F, or put more readily, a ¼ inch Whitworth. You will also need a tube needs of ¼ inch inside diameter. The easiest way is to is to get a "one man bleed kit" with a one-way valve in the tube and fix air tight connectors to the ¼ inch tube. If this does not appeal, then get an assistant to push the brake pedal for you. Also have a spare tin or two of clean new brake fluid ready to top up the reservoir: it empties very quickly and you will get air into the system if you are not careful.
DO NOT MIX SILICON WITH HYDRO BRAKE FLUID - IF IN DOUBT GET A GARAGE TO DO THIS FOR YOU - YOUR BRAKES ARE YOUR LIFE!
Once set up with the tube over the nipple, the assistant (on command from you) should push on the pedal, then you gently slacken off the nipple, (loosen it first then just 'nip' it up ready). The oil will squirt out into the tube, so have another container to catch the outflow. Their foot will go to the floor. THE ASSISTANT MUST NOT RAISE THEIR FOOT until you have nipped up the nipple. Once you have 'closed' the nipple they can raise their foot. Keep repeating this until you get clean fluid coming out of the tube. Use clear plastic as you can see it ejecting from the nipple.
The first drum will take ages, but once you have clean fluid into the system the others will quickly get clean fluid. Always do the NEAREST to the master cylinder first, i.e. the drivers side front (RHD), then the n/s front, then o/s rear, then n/s rear. Top up the reservoir to about ¼ inch from the top, leaving a small air space in there for expansion in hot weather.
Try to avoid getting fluid on any paintwork. Keep water handy to wash it off if you do, it will dissolve in water. Use lots of water. Do not get any water in the system.
Neil Cairns, UK
If this is done without lifting the body from the chassis, the chassis can be used as a 'jig' to support the body. Only one side can be done at a time, or all reference points are lost: it really depends on how much of the sill has rotted away. If it is only the bottoms and forward end, this can be 'patched' using sheet steel. If done properly and let into the sill, it can be almost undetectable. Obviously both side (front and rear) wings and the Running_Boards need removing. Alas this is where MORE rot will be found, especially at the rear end. If complete new sill are required, the doors will need to come off as well, and the side of the car supported to maintain door gaps, etc. This is rare as the top edge and uppermost inner sill usually survives. The rear end of the sill has a complex mounting point that rots out, just in front of the rear seat wall, again more expense.
Neil Cairns, UK
Spark Plugs - short reach
If you have an early XPAG engine that uses short-reach spark-plugs, try going to your local garden centre lawnmower desk, or your local motor factors. The modern equivalent to a Champion L10S is sold as a KLG, and used in the Briggs & Stratton engines in garden machinery. Usually sold for about 65p each, cheaper than some MG specialists.
Neil Cairns, UK
Loss of Oil Pressure
Recently I suffered a sudden drop in oil pressure (and erratic reading) in my YB and feared the worst. However after much investigating and thinking I discovered it was the short piece of rubber tubing connecting the oil pressure feed lines to the instrument where it enters the bulkhead. The tube had perished and become porous. I'm not surprised because it looked original. It was leaking oil and probably air was getting in as well worth checking because it could save taking the engine out!
Ted Gardner, UK
Wishbone Arm Bushes
When renewing the Wishbone Arm Bushes in your Y Type (or T Type) replace them with MGB V8 ones. The part number is BHH1123 (Moss and Brown & Gammons) or R135A (NTG). The V8 bush fits inside as opposed to the standard bushes that push in from either side. With no lip to the bush they are stronger, more durable and as you only need four as opposed to eight, cheaper!
David Pelham, UK
Engine tie bar and water pump damage
Damage to your water pump casing can easily be caused by the end of the tie bar on the YA/YB/YT. The engine end is located tight under the water pump in a U shaped "cup", and is difficult to examine unless you use a small mirror and a torch or remove the radiator. The rubber bush washers rot away, and the bracket then gets a lot a hammering from the torque of the engine as the throttle opens and closes. The tie bar is there to resist this torque. Once loose, the end of the bar will punch a neat hole through the pumps casting. To check this, 'rock' the engine from side to side. You have a problem if you can hear the end rattling. There should be no movement. Correct adjustment is shown in the manual and new rubber washers are available from the Octagon CC and NTG.
While you are inspecting this you might like to check the other end of the tie-bar as well. Movements at the other end of the tie-bar can lead to a neat crack right across the middle of the fabricated bracket that bolts to the cross member - less potentially disabling than a hole in the water pump, of course, but offering no torque reaction at all. It is worthy of note that there are FOUR bolts holding down this end. This bracket bolts to the cross member and to the top two rear bolts that hold the right hand, (off-side in the UK) damper. Sometimes these are not tightened fully, as they are difficult to get to.
Neil Cairns, UK
Hubcap removal - without chipping the paint
Removal of a hubcap, even using the special adapter fitted to the end of the wheel brace can often lead to a chipping of the paint on the wheel. To prevent this, make up a wedged shaped tool about half an inch wide from a hard wood, use it to flick off the cap. The screw driver chips the paint because of the high loading on a tiny area.
Hubcaps falling off
Over the passage of time the small studs which should hold the hubcaps onto the wheel rims become worn, the hubcaps no longer fit securely over them, and fall off as the car goes over a bump. A remedy for this is to buy a length of heat shrink sleeve (about 3⁄8 inch inside diameter before shrinking) from your local automotive electrical supplier. Cut off 3 pieces about ¾ inch long, slip them over the wheel lugs and shrink them in place with a hot air gun. Next, try the hub caps in place. If they're still a bit slack, shrink more sleeve over the top until the caps are a snug fit. I found that the inside diameter of my new hub caps varied slightly, so it was necessary to vary the amount of sleeve to suit each cap.
Bill Bennett, UK
You can write your name and phone number inside the hub cap, if you lose one off your precious Y you may receive a call from the hub cap finder. My YT has a previous owner name inside the hub caps. A piece of history about my YT.
David Ward, Australia
Spare wheel replacement
I am running 15" wires on my YT3208 and had a special spare wheel made which is 15 x 4". I have fitted a 135 X15" Michelin Tyre which is available for small Renaults and fits easily into the spare wheel compartment inflated. You cannot drive far on it but enough to get you to the nearest service station.
Richard Prior, Australia
Fitting the sump
Fitting the sump from below is difficult because of the rear seal and the weight of the casting. This is even more so in the last larger sump cars as the sump is heavier and there is less clearance to fit it at the front of the chassis. It is of course essential to maintain the integrity of the rear seal by keeping the sump absolutely square as it goes home and not moving it about to locate the bolts. To assist this I replaced the four corner bolts with studs. I seem to remember they are 8m.m. fine but you will know better than I do. I again made these by cutting the heads from 60 mm. length bolts and restored the thread with a nut after filing a chamfer. These extra long studs allow you to keep the sump absolutely parallel and square as it slides upwards and into place and there is no problem locating the remaining bolts because they and the gasket are lined up. If purists are horrified at replacing those rather nicely made slotted bolts with long home made studs they can unscrew the home made studs and put the bolts back in after screwing home the other bolts. Hope this is of use it certainly did the trick for me and because it will always allow the sump to be quickly and easily refitted I have left my home made studs in place.
Phil Waltham, UK
Rear Hub Splines - (peculiar to YBs)
Recently I was checking the rear brake shoes on my YB during a routine service. I was just about to refit the rear off-side brake drum, when to my horror I noticed that the splines on the inside of the drum were just about non-existent. They had worn away to about 1mm, whereas they should have been 7-8mm with a similar sized gap before the next spline. The gap between the remains of the splines was thus around 14mm! The end of the half shaft had some damage to the splines but far less, presumably the steel used for the half shaft is more hardened. Fortunately, I made the discovery on my drive, as the remaining 1mm on the drum could easily have sheared through at any time, miles from home. I checked the near-side drum and found similar but less severe wear to drum and half shaft.
Left to right - Worn hub and new hub
Drive shaft splines - note the notching
I believe the reason for this was that I had mistakenly left a little play when tightening the large hub nuts after fitting new oil seals - I should have tightened these nuts forward before fitting the split pins, whereas I had slackened them back slightly instead. Any other theories?
I decided to fit another complete axle rather than just halfshafts and drums and fortunately I was able to buy a second hand one from Andrew Booth. A good friend helped me to fit it a week later, just in time for me to take part in the Golden Jubilee Classic Car Show at Greenwich this year (2000).
David Hague, UK
Removing the radiator - the easy way
My car features a modification which was done to my car long before I acquired it (for a long time I was not even aware that it was a "mod"), it is so logical and neatly done I thought it must have been a factory fitting.
I am talking about a modification to the headlamp holding tube which connects the headlamps on each mudguard and passes through the radiator shell. You will be aware that to remove the radiator one has to first disconnect, then remove, the headlamps. The modification I have (and now a number of other people in Sydney who have copied my car) obviates the problem of taking off the headlamps altogether. I can now get my radiator out of the car in 20 minutes on my ownand replacement takes about the same time. All that is required is for the connecting tube between the headlamps to be replaced with a stainless steel bar of the same diameter. This bar is suitably cut and "filleted" at each end so that the bar is in three pieces with right angle joints at each connecting end. The smaller end pieces are each fitted into the chromed fitting on the mudguards and extend just outside the headlamp clamp. The longer part of the bar is connected to each side by a counter-sunk, un-obtrusive set screw at the joint and the longer part is that which passes through the radiator shell. After removing the bonnet, to remove the radiator all one has to do is disconnect the radiator stay rods on each side, take off the hoses, undo the two bolts holding the radiator to the bottom frame, disconnect the two bolts holding the radiator bar described, and lift the whole radiator up and out, the headlamps are not touched. The pictures are provided by Peter Martyn and a zip file can be downloaded here.
Alf Luckman, Australia
Radiator expansion tank
I know, with your cooler weather, this may not be an all-consuming problem but in the hotter climes of parts of the old Empire, overheating does become a difficulty at times. A friend in Sydney has developed a clever idea which attaches a sealed vertical, 1 point 5 inch, copper tube to the left hand lower part of the radiator, this is connected through the bottom of this tube, to the overflow pipe from the top of the radiator and catches any outflow from the header tank, so that the coolant is not lost. On reaching the top of the hill or slowing down, the radiator cools slightly, the caught water is then drawn up into the header tank again and all is well with the world. The radiator cap needs to be tight to provide a good seal, my friend tells me the device works very well indeed and had caused him no problems. This device also needs a couple of photos to suitably explain and these can be down loaded in a zip file here.
Alf Luckman, Australia
Cleaning Grill Slats and Chrome
If you live in Australia or those parts of the world that have lots of bugs in the summer months you will know what a pain in the butt it is to get those baked on hoppers, insects and bugs off your chrome radiator shell, grill slats, bumper bar even paintwork. Solution - buy one of those soft woven aluminium strip, non stick pot scourers with the foam pad inside. Run it in well by helping your wife do the dishes a several times then with soapy water and light rubbing they make an excellent debugger that will not scratch. Particularly the grill slats because you can push it between the slats and simply slide it up and down.
Richard Prior, Australia
Fitting Seat Belts
Noting a comment by one of the owners of a car on the "Parade" I thought my experience of fitting a seat belt/harness in my car may be of interest to other people. Being fully conscious of the benefits of seat belts and very aware of the lack of that safety factor in our favourite old cars, when I restored my car I went to some trouble to check out the whole scene.
First off, take out the front seats, the carpets and the floor boards so you can see what you are doing. Because of the wooden floors of the Y - the first requirement is to have a decent steel plate welded onto the chassis rails on each side about level with the rear of the front seats. This must be matched with similar plates welded to the inner framework which carries the transmission tunnel/handbrake.
These plates need to be carefully filleted onto the metal bases at the four points and beneath the floorboard level to provide the necessary strength. Later you will need to drill through the wood and the steel plate in order to fit the holding bolts for the ends of the "lap" part of the belts you are going to fit.
At that point you can stop and fit a "lap" type belt which will keep you in the car in a smash and not have you disappear out the "suicide" front opening doors.
That takes care of the first part. Next you will have to decide if you are going to fit a "three point" belt and if you do, you have to make up your mind where the "shoulder" strap is to be anchored. If you are fairly short in stature (or vertically challenged) and you drive with the seat as far forward as it will go you may, repeat may, get away with bolting the third point through the top of the pillar on which the doors are hinged.
This arrangement would be awkward as this pillar is not all that strong and should be filled up with trafficators and associated wiring. However, if you do not have trafficators fitted (shame) the pillar can be re-enforced and the "shoulder" point bolted through, this will (probably) leave the bolt head exposed on the outside of the car.
Now comes the crunch....if you are of average height or a bit taller, you will no doubt already be aware that you sit so far back from the steering wheel that when you turn your head to the right you look out the window of the rear door. As such it is absolutely useless fitting the "shoulder" anchor point to the centre pillar as the seat belt strap will be under your chin. Besides being uncomfortable this arrangement will decapitate you in a decent prang.
An alternative I have seen fitted to another car, (not a Y) is to weld a reinforcing plate to the roof of the car above and behind the driver's seat and anchor the belt to that. I would suggest that method is a major project and would only be practicable if you have all the head lining out and the car is undergoing a total rebuild.
The route I followed at this point, having discarded the idea of the three point belt system, was to fit a full racing harness and anchor the shoulder strap(s) to the top of the rear deck under the rear window. This part of the car is immensely strong and is the right height to accommodate the fitting bolt.
The disadvantage is that if you are carrying rear seat passengers the belt to the rear ledge gets in the way. I overcame this problem by fitting an approved racing harness which can be "broken" behind the shoulder strap and leave only a "lap" belt for the front seat occupiers.
It is not a total solution and the rear seat passengers don't have a belt at all but in my case that has not proved a problem.
I imagine it would not be too difficult to fit belts to the rear seat if that is what you need.
One last warning, don't be tempted to fit a shoulder strap straight down behind the front seats to the floor area. The distribution of forces in a solid smash would probably keep you in the car but you will end up with two broken collar bones.
Alf Luckman, Australia
Full notes on Roy Clapham's installation can be accessed here.
Feed the leather seats once a year, the cream can be found at saddlers, tack suppliers, antique shops, Woolies interior-trim specialists, and good MG suppliers. Rub it in well and polish. Those supple leather seats will last for years, and the interior smells nice. Two useful links on the Woolies site are http://www.woolies-trim.co.uk/p-1032-no-1-leather-renovation-kit.aspx and http://www.woolies-trim.co.uk/p-1033-no-2-leather-renovation-kit.aspx.
The heater circuit in my YA never warmed up even though water would flow through it with the return pipe disconnected. I'm pleased to say that I have located a suitable pump at a ship's chandlers. It is a Zambezi Inline Pump LVM 160 manufactured by LVM Ltd. (01462 733336). Various pumps are available, but this is continuously rated (4.5 Amp) and is suitable for hot or cold water. I bought it from MarineForce Ltd (0870 010 4885 email marineforce.com) for about £30. Since the flow rate of 18 L/min is a bit high I added a loop back from outlet to inlet. It needs fixing in such a way that that there is a head of water to prime the pump. While plumbing it in hardly any water escaped from the heater hose. After testing and adjusting the hoses, water gushed out. It had solved my problem but not in the way expected - it had pumped out the airlock in the system. The heater now works well without the pump running, but benefits from an extra boost when the weather is really cold. David Mitchell-Gogay Y7012 UMG422.
XPAG Water Pump Potential Problem
The replacement pattern water pump is supplied without an essential washer. It is easy to be misled into thinking that all that is needed is supplied as the pump comes complete with Woodruff key and stiff nut, so it appears that all one has to do is slide the pulley in place and secure with the stiff nut. The seemingly insignificant washer is not supplied; probably because it is a non-standard size. However, without this washer distributing the load only the outer edges of the stiffnut bear onto the edge of the pulley recess, while the centre of the stiffnut is pulling tightly on the thread of the shaft. With the side pull on the pulley by the driving belt the net result is that the inner surface of the stiff nut becomes bevelled and resembles a small wheel nut!
The pulley will wobble around and subsequently enlarge its hole. Eventually the Woodruff key in the water pump shaft becomes so worn that the pulley will rotate without driving the pump. With no water temperature gauge it could prove to be an expensive washer!
It could be worthwhile adding the 30 second physical check of the pulley to your servicing schedule. (See diagram for correct location of washer.)
Also concerning the pattern water pump and pulley is the fact that the the felt washer and its retaining cover shown on the diagram appear to be no longer available, and probably not needed since the pump bearings are now double sealed. However, as the pattern pulley is not bevelled, as the original, it bears onto both the inner (rotating) AND the outer (fixed) surfaces of the bearing! So either turn a bevel onto the rear of the pulley or make another small washer to fit where the retaining cover would have been, but limiting its outer diameter to that of the centre of the bearing. (Another example of pattern parts not being made to original specifications.)
Peter Cornelius, UK
Fitting a new Windscreen Seal
Y type restorers and those folk who just have an urge to replace the windscreen rubber seal on Y sedans may care to note that recent experience in Sydney has shown that one (if not the best) lubricant for passing the new seal around the chromed windscreen is - wait for it - lard. That's right - lard - the stuff people use for cooking and other culinary pastimes and is as cheap as chips to buy. A wearying experience several years ago by the writer, of using almost every know type of lubricant including, graphite powder, water dispersant lubricants, engine oil, washing up liquid, elbow grease, not to mention bad language, all in copious quantities, finally prevailed but at the time I swore never to do the job again. Then a friend asked a little while ago to help him do a similar job on his car. I sought ideas on the Net from the Bulletin Board on suitable lubricants. Many and varied were the responses including one from Neil Cairns who suggested K Y Jelly. Probably good in theory but I was not game to try it. Even if I knew what K Y Jelly is! Paul Barrow came up with the suggestion that Lard would do the job. He had read somewhere that the ancient Romans used it for lubrication purposes in siege engines and other contemporary weapons of mass destruction. This was during the period when the Legions were doing their bit for European ethnic integration and spreading the word to the ignorant masses they had to wipe out to make them see the benefits of civilisation.
Anyway a packet of lard was purchased (at about one tenth of the cost of a tube of KY) at the local supermarket - the new rubber -obtained from the only know supplier in Christendom (NTG Services) was worked around the windscreen fairly easily and after only 30 minutes of messy fun the job was completed. It really is necessary to remove the windscreen from the car before attempting the job but that is easy - just undo the two bolts holding it to the swinging hinges. It is also a two handed job - well, actually four hands, but you know what I mean, and if you work on a small table you can walk around, it is even easier. As they say in the classics - replacement is the reversal of the removal.
Alf Luckman, Australia
Fresh Air Motoring
I sometimes drive my Y with the front window open, although the length of time I am able to bear the increase in noise levels from the engine prevents me from doing this too often.
If I decide to open the window, I first centre the Windscreen_Wipers. If they are not centred before the window is opened, they are blown into the car as you drive along and will flap around causing some distraction.
If they are centred first they will be blown against the operating chain and will not flap about within your view.
Jack Murray, UK
Gearbox Refit - Speed up
To speed up refitting of the gear box, screw 2 head studs into the engine block to act as guides to slide the gear box on to for alignment purposes. Studs can be removed after you fit a couple of regular bolts. Do not forget to reconnect the gearbox / engine earth strap!
Gearbox Removal - Speed up
One of the few design faults with the MG Y series is that the toe board (the bit that the dipswitch is fixed to) is made from a single piece of metal. Therefore if you want to change the clutch or remove the gearbox for any reason then you need to remove the throttle pedal, cable etc before you can remove the toe board. In order to speed up operations, both removal and refitting, cut the toe board in half. The place to cut is at the top and in the middle. When you subsequently need to remove the gearbox you need only remove the toe board on the passenger side. The driver's side can remain in place and there is no need to remove the throttle pedal. The concours judges will never spot this, as your carpet will cover the evidence.
David Pelham, UK
Rear End Rust Prevention
Unfortunately the XPAG engine oil does not reach as far back as the boot on a Y Type and therefore the metal-worm frequently attacks the boot and spare wheel cover. In order to ensure that any water is not "captured" for longer than it need be in the spare wheel cover and boot surrounds, ensure that the sealing rubber is placed around the top half of the area rather than the whole area. You will suffer from less rust if the sealing rubber is not fitted to the bottom half of these areas.
David Pelham, UK
Brake Light Switch
The brake light switch fitted to Y Types is located in the Pedal Box. It operates by having a spring connected to the brake pedal, which when depressed completes a circuit and lights up the brake lights. It has two disadvantages in that it is 'all or nothing' the brass contacts either make a connection or they don't; as it is located in the pedal box the brass contacts can get 'grimed up'; with grease and other muck that can find its way into the Pedal Box. If you are restoring or have a faulty switch it is better to fit an in-line brake switch. The YB has 3⁄16 brake pipes and can use an in-line pressure switch from a TD. However, the YA and YT have ¼ inch brake pipes and need a special in-line pressure switch. I commissioned a special run of these. The in-line switch fits on to a dual banjo union that connects to the back of the master cylinder. I managed to fit mine using the same brake pipes! The complete kit was available from the MGCC Y Register, but is no longer stocked; it is possible that I may be able to organise a further run if anybody is interested.
David Pelham, UK
As seen on the MG Bulletin Board
Remove the spare wheel before drilling the holes in the piece of wood separating the spare wheel from the boot!!!! (Anon.)
Rear Cover Plate
Whenever you have the engine out be certain that your rear cover plate is in good condition. Ideally get one of the brass or aluminium replacements from the MG Octagon Car Club. If it leaks remember that unlike the TD somebody butted the Y Type battery box up tight to it. The easiest way to replace a leaking cover plate is to take the engine out again.
David Pelham, UK
The Jackall Handle is located in the Spare Wheel Compartment but it fits nicely in the top of the bracket that fixes the bulkhead to the chassis, beneath the coil. I leave mine here as it is more accessible. The space in the spare wheel compartment can then be used for your spare half shaft.
David Pelham, UK
If your welding is perfect then this is not for you. However for the rest of us, getting captive nuts on the sills is relatively easy, getting them to align with the Running Boards can be a different story. A good solution to this problem is to use 6mm Clinch Nuts. The Running Board can be held against the sill and the location of the desired bolt can be marked exactly. It is then easy to drill the hole, fit the Clinch Nut and bolt up. If the thread goes on one of your existing captive nuts you can bore a hole alongside and fit a Clinch Nut. It has worked well on my YT.
David Pelham, UK
Of Carburettors & Dipsticks
Each time you check your oil level, when you have withdrawn the dip-stick, let it drip onto each end of the carburettor butterfly, (throttle valve). This is a brass spindle and it runs in a Mazak casting, and wears quite rapidly. A little oil often ensures a longer life, and more even running through less air leaks.
Neil Cairns, UK
If your car stalls on a very hot day, and you have been moving in a slow queue, douse the carburettor body in water from your windscreen squeezy-bottle before you try to re-start. The stall was caused by the petrol vaporising in the float chamber, and to re-condense it cooling it with water really works. Otherwise you will flatten your battery before it fires up. Fit a Paxaline insulation block between the inlet manifold and the carburettor body ASAP. One from a Morris Minor/998cc Mini fits, but cut it in half length-wise or you cannot get the nuts onto the studs (they are too short). Re-route the fuel feed pipe away from the exhaust pipe run, to stop the fuel vaporising in it. Today's lead-free seems far more prone to this fault.
Neil Cairns, UK
Carry an old washing up liquid squeezy bottle with water in it, for squirting at your dirty windscreen, and at the carburettor on hot days.
Neil Cairns, UK
Keep a spare windscreen wiper and arm in the boot, today it is common to have them stolen and driving home without one fitted is 1) dangerous, and 2) illegal.
Neil Cairns, UK
Buy a MGCC tax disc security holder. These stick firmly to the windscreen, and have a clear disc stuck over the tax disc to stop them being altered. Such things as paper discs are easily stolen at meetings a rally's where you left your car windows /doors open, but not missed until you next wash the car.
Neil Cairns, UK
Beware buying nice fat radial-ply tyres for your 'Y' type. They will not fit into the spare wheel compartment. Some you can deflate to fit, but you need to carry a foot pump. Carry a puncture outfit and some tyre levers. That way you will never need them.
Neil Cairns, UK
Always change the engine oil before you put the car up for winter, not afterwards in the spring. It is far better to store an engine with clean oil in it. Old oil contains a lot of water in suspension, and combustion acids. These can soon eat away white metal and bronze bearings. Remember used engine oil can cause skin problems to your hands, use a barrier cream.
Neil Cairns, UK
Grease king-pins and brake cables until clean grease come out, pumping out all the used muck. Clean it all away to keep dirt out of the bearing surfaces. Rub the used grease up under the chassis and under the inner sill areas, it helps keep corrosion at bay.
Neil Cairns, UK
Gearbox / engine earth strap
Always check that the earth strap is securely refitted to the bell housing bolt and chassis after you have finished. Failure to do so may result in high current passing back to earth from the starter motor by the quickest route. This is normally either the choke cable (which could either give you a shock or turn into high quality fuse wire) or up the speedometer cable. This second route can also be very expensive as it will cause your speedometer to seize up resulting in the snapping of your speedometer cable and necessitating a complete rebuild of the speedometer - this is from bitter experience!
Paul Barrow, USA
Broken Speedometer Cable?
Has your speedometer cable snapped? Check the fitting and security of the Earth Return Strap (as above) and before fitting a new cable use the free ends to see which end of the cable the problem is located. A snap at the gearbox end indicates the problem is at the speedometer head. A snap at the speedometer end indicates the problem is the gearbox drive gear. Take the snapped cable ends and insert the end into the back of the speedometer and try to turn it. If the speedometer is free you will be able to turn the cable easily in a clockwise direction (speedometer facing you). If you cannot turn it - it is seized. Now do the same with the woodruff key end into the gearbox. With the rear wheels off the ground and the front wheels chocked, you should be able to get the cable to turn by rotating the propeller shaft. Failure to track the problem, and merely assuming it to have been the age of the cable will result in you having to fit another cable when you replacement quickly (100 yards or so) snaps again. Also from bitter experience! See the related Technical Query.
Paul Barrow, USA