G-Machine camber bushings

[Seppi72]

I am in the process of installing G-Machine camber bushings (purchased from MSA) in my '72 - replacing the urethane ones that have been in for almost 5 years - and have a question. How does one actually adjust the rear camber with these things, especially with the flimsy "tool" that MSA sells for this purpose?

The rear bushings are located at the pivot points for the rear A-arms and are aluminum cylinders with thin, hexagonal end plates and offset holes for the A-arm tube. The tube ends are isolated from the aluminum with polyacetal (Delrin) bushings that are inserted from either end of each assembly.

Now, the aluminum part is what is supposed to be turned using the so-called tool in order to adjust the rear camber. The tool is a piece of sheet aluminum with an appropriately sized hex pattern (four sides of the hex) cut into it. It looks like a smashed line wrench but without the vestigial fifth and sixth hex segments. I could post pix if that helps anyone, but as my question is directed to folks who have already used these things, they are unnecessary to the matter at hand.

So, here's the problem. The aluminum bits are supposed to be turned and yet they are the parts that are clamped into place by the brackets that attach to the unibody frame. Even if I were to install grease fittings, I don't see how the bushings can reasonably be expected to turn while clamped.

Now, someone might say you jack up the car, loosen the clamps, and adjust them. Yeah, that might work, but because you're ostensibly trying to adjust the camber, how is this done easily (or at all) when the car is on an alignment rack?:stupid:

The issue isn't quite as dire for the front bushings as they (1) have the aluminum bit inserted into the Delrin parts, (2) go inside the front control arm, (3) aren't clamped into position so much as held by torque and (4) have a much wider hexagonal end with which to work. The MSA tool is still a thin piece of aluminum sheet, however.

Those of you who have (or had) these bushings installed are requested to reply with your experiences, observations and, I hope, work arounds. I want to decide whether these go on or get switched out for the urethane ones this coming holiday weekend.

Edited May 21, 2009 by Seppi72

[jmortensen]

Loosen the clamps, rotate the bushings, tighten the clamps. If the car is on an alignment rack, the mechanic should be able to crawl under the car, loosen the clamps and adjust without too much trouble. When I was working as a mechanic I used to adjust my camber bushings before every autox, just trying out different toe settings, etc. DO NOT GREASE between the bushing and clamp. These things have a bit of a tendency to move on their own, so you don't want to facilitate that movement. Example: http://www.classiczcars.com/forums/showthread.php?t=34306

Some guys use set screws to hold the bushings so that they cannot turn, but that only works if you know where you want your alignment to be permanently. If you're playing around trying to find what you like best you don't want to install set screws. I've also seen it suggested that you put some emery cloth between the clamp and the bushing to provide more friction and make it harder for the bushing to rotate on its own. They used that emery cloth that has perforations in it and is more like a mesh than a sheet of sandpaper. Sorry, don't know the technical name for that stuff.

[Seppi72]

Great info, Jon, and it figures to be comng from an experienced hand like you. That's the vaule of this site. BTW, I cross-posted this on HybridZ.

My big probelm is that I can't even seem to get the bushings to turn when the car is on jack stands with the wheels off. I literally began to distort the "tool" while trying to do so. I can't imagine how a mechanic unfamiliar with these bushings would begin to use it even after I explain the process.

I'm considering having the tool, which I recognize is really the only thing that easily works in the space allowed, being copied in hardened steel plate. That would likely solve the problem and I could put a proper handle on the damn thing.

The other approach I've thought of is to drill holes into the flats of each side of the hexes and build a "pin wrench" that would lock into any hole for adjustment purposes.

[jmortensen]

I never owned the actual tool. I used to back off the big 24mm bolt in the end of the arm and grab the bushing with channel locks. Yes, they did end up digging in and messing up the corners of the bushing, but channel locks moved the bushings without too much trouble.

[Seppi72]

It sounds as though you are talking about the front camber bushings and, if you are, I agree that they are way easier to adjust. In fact, I have an old adjustable wrench that works well on them once I welded it at the correct opening and ground off some thickness.

My problem is with the rear bushings because of how they are designed and attached to the car.

As an aside, the reason that I want to have these things on the car is that it is about to get back on the road after being repaired from the crash that I had last September. We had to replace the left front frame rail and, even though the body shop checked and verified all the front dimensions, I want to be ready and able to correct any small crookedness in the rear when the car is getting aligned.

[jmortensen]

No, I never used the front camber bushings. I am talking about the rears. You take the large 24mm bolt, back it off maybe 8 turns or so, and that will give you room for a wrench or a pair of channel locks. It's been a while, but I think a wrench is a PITA because you have limited room to move in there.

[Seppi72]

Ok, Jon, I'll give it a try later today or tomorrow. I figure there has to be a way or MSA and Black Dragon wouldn't be selling the kits.

[gnosez]

Once the bolt(s) are loose, then for the fronts you use a channel lock and the rears you can use a flat punch pin and a hammer. If the fronts don't turn then you need to spread out the crossmember.

You'd be doing this to get your alignment settings so once they are done then you tighten the bolt(s), mark your settings in some manner (paint, scratch, etc.) and go drive your Z.

The tool, if one could call it that, is worthless. Throw it out.