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TECH TIPS
Wire Wheel
Conversion
this is an excerpt from the articles appearing in the
OCTAGON
also see upkeep and performance hints on our message board at board.mgclub.org
Wire Wheel Conversion
Q: I am planning on updating to wire wheels on my '72 roadster. I have read up on some tips and was wondering if you had any tips. Is it a good idea to replace 6 leaf with 7 leaf assembly? I have been told they will fit and give it a stiffer ride. I will be changing the rear differential for spline drive so it seems time to replace the original components with new ones.
Should the front wheels be on car ramps? I also intend to support the car with jack stands in front of the front spring eye mounting points. Will the car rock when I use a floor jack to take the tension off the rear axle? This will make unbolting it easier. I understand soaking everything overnight with liquid wrench will help. This a big job and hate to make any headaches. I plan to use the harder urethane bushing kit. Any tips for the job would be really appreciated. Thanks for the great work.
Bob Tresch
A: I did this conversion on my '73 B some years ago. I used a '74 donor car as the body was badly damage. I took the rear axle and front suspension for my car and much of the rest found new homes in other's cars as well. I love the look of the chrome wires, but do miss the ease of maintenance of the discs as I use mine as a driver.
Before I address your points as presented, some notes you should have:
- The rear axle of the wire wheel B is about 1 1/2" narrower than that of the disc-wheel axle. Unless you are changing the entire axle (or using the splines from the specially designed conversion kit), just adding splines to your axle will cause the tires to hit the bodywork.
- The narrower axle requires a different handbrake cable. Don't try to salvage or adapt your existing cable as it will not fit or work correctly and will likely be damaged in removal anyway. Just change it outright.
- Be prepared to refit the front and rear
brakes. That includes all shoes, pads, flexible hoses and wheel cylinders and rebuild the calipers.- In changing the front hubs, make sure you have a shim kit available, new bearings and grease. Having shims in various sizes is important as not all the hubs are machined the same and these bearings are not preloaded, as in more modern designs. Too tight, they bind, too loose and they float. To your points:
I would support the car on (4) solid jack stands. The front either under the cross member or the spring pans (if you intend to remove the spindles). The rears, as you said, should be supported just in front of the forward spring mount, though check the condition of the floor pan there to make sure the top does not go through and also to leave room for access to the front spring mounting bolts. I tend to use stands with round tops (better to have "U" shaped tops for supporting axles, but those can do damage to sheet metal) and put plywood both on top of the stands at the back and under all 4 on the floor. The wood at the front of the spring mounts distributes the load some, putting less of a strain on any point of the sheet metal. If your garage floor is blacktop or smooth concrete, the wood bases tends to both protect the flooring from damage and keep the stands a bit more stable. They should be a bit larger than the base of your stands. Do not rely on floor jacks, scissor or bottle jacks as they are not stable enough if you get to banging around the stuck pieces.
The 7-Leaf springs would be a good idea, but they are heavier than the already weighty original ones. Consider instead the "rally tuned" 6-leaf springs or new parabolic designs which are only 1 or 2 leaves, much lighter and perform as well.
Panhard rods or other anti-sway devices are a very good idea. Later B's had them standard and those can be sourced used or new from the catalogs. I have the urethane bushings in my car and swear by them. Besides the improvements in handling, the longevity is so much better than the rubber, as well they are not subject to deterioration by oil from the car or road.
Using a die grinder or other circular cutter is easier to control and get into tight places. If you have a compressor, air driven tools are better, as electric cutters tend to either runaway or whip if they bind, where air cutters just stop and by pass the air. I did not really need one as I found, after soaking the bolts and shackles with penetrating oil, most everything came apart, if not cleanly (some bolts were not reusable), at least completely. One thing that did play in, not on my car, but on another fellow's car I helped with, was the "U"bolts that hold the axles to the rear springs broke-off at the nuts, even with using oil and heat. We were able to find replacements at the local NAPA store, though those required drilling the holes in the metal pads/shock mounts under the spring slightly larger. They are available from the catalogs, so if yours look bad, you might want to plan their replacement before you start. If you plan on going to the salvage yard for the axle, make sure you check a few things on the axle you plan to purchase:
- The splines are rugged, but subject to wear. Too much and they could be dangerous. Might be good to replace them anyway, but make sure you have the wear guide (found in the Haynes or other manuals, which you might find in the library).
- There are (2) fiber thrust bearings in the differential that cushion the spider gears (referred as "differential wheels" in the VB catalog) to each side of the axle. These tend to wear, crack and drop out of place. The result is that annoying 'click' on acceleration/deceleration. The replacement (now bronze or copper) are cheap, but it means taking the diff apart to fix. Rotate the axle shafts back and forth to see if you hear that click, if just to what you are in for with the new axle.
- The area where the U-bolts go over the axle tube tends to corrode. Too much corrosion and the tube could be porous or weak.
- The bolt that supports the rebound strip (top of he axle) is on some variations welded in place. These, too are subject to corrosion at the sheet metal support, so could be weak, cracked or missing entirely. Repair involves welding a new one in place.
- Make sure the back cover is in decent shape (or the one from your old axle is). The hand brake has a bracket there that is often missing to damaged. You need the pivot to be secure and in place for it to work if you intend to have the parking brake active.
Be sure to check the axle if you are getting a different one. The splines are rugged, but subject to wear. Too much and they could be dangerous. Might be good to replace them anyway, but make sure you have the wear guide (found in the Haynes or other manuals, which you might find in the library).
- There are (2) fiber thrust bearings in the differential that cushion the spider gears (referred as "differential wheels" in the VB catalog) to each side of the axle. These tend to wear, crack and drop out of place. The result is that annoying ‘click’ on acceleration/deceleration. The replacement (now bronze or copper) are cheap, but it means taking the diff apart to fix. Rotate the axle shafts back and forth to see if you hear that click, if just to what you are in for with the new axle.
- The area where the U-bolts go over the axle tube tends to corrode. Too much corrosion and the tube could be porous or weak.
- The bolt that supports the rebound strip (top of he axle) is on some variations welded in place. These, too are subject to corrosion at the sheet metal support, so could be weak, cracked or missing entirely. Repair involves welding a new one in place.
- Make sure the back cover is in decent shape (or the one from your old axle is). The hand brake has a bracket there that is often missing to damaged. You need the pivot to be secure and in place for it to work if you intend to have the parking brake active.
Safety Fast!
Art Isaacs
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