C3 Half shaft flanges hitting

[Tom R.]

I am at the same place in reinstalling as I was disassembling and am having a geometry problem. I basically have a complete rolling chassis minus the engine and transmission. The rear shocks and rear stabilizer are not connected either. At this point during the disassembly phase I could freely roll the chassis by hand. I have restored/used everything original except I have replaced the rear control arms (Bairs). I cannot roll the chassis due to the half shaft flanges hitting the side yokes from the differential. I did not have this problem during disassembly even though most of the weight was removed. The rear height is way off by about 3 inches judging the vertical distance between the ends of the rear strut rods (D-dimension). I have the strut camber adjustment cams at the flatest point. I realize that this will change with the addition of the body but I can't imagine by this much. I can't install the shocks because the distance is too great between mounts. If I force the ends (rotate) of the control arms up I realize that the half shaft problem will be solved as well as the shocks. If I do so mechanically, and connect the rear stabilizer to the end of the control arms will this serve to prevent the spring from pulling down and alleviate my problem for now? During disassembly, the shocks and rear stabilizer were connected while I was rolling the chassis around. Just scratching me head trying to determine why the huge difference in now and before??? I feel as if I've overlooked something simple but can't see the forest for the trees.

[Patrick H.]

Re: C3 Half shaft flanges hitting

The difference could be 1) anything you did to the spring (replaced it, added new liners) and/or 2) new end bolt cushions for the spring. Notice that they're over an inch thick, compared to the squeezed and flattened ones you removed. This will add 2 inches to your height and cause this exact problem.

Put weight on your chassis in the area of the gas tank (couple hundred pounds) and roll it back and forth. It will probably settle a bit, though not fully.

Patrick

[Michael G.]

Re: C3 Half shaft flanges hitting

I know that once the shock is removed and the trailing arm has swung downward beyond the distance that the fully extended (attached) shock would allow, the binding at the joints occurs. I believe that the strut rod (attached) will somewhat limit the downward throw of the arm and possibly avoid the binding. But to have these both removed at disassembly and not have a bind at the joints is unusual.

[Tom R.]

Re: C3 Half shaft flanges hitting

Patrick, I did replace the liners in the spring and that's a good point regarding the new spring cushion bushings as well. I know adding weight at the rear will solve the half shaft bind but just don't understand why it wasn't binding/hitting when I removed all the weight during disassembly. I'll load it up and get the rear stabilizer connected and shocks if possible and see if that'll ge me enough to move ahead until the body drop.

[Joseph K.]

Re: C3 Half shaft flanges hitting

Pictures would help use see what the problem might be.

[John H.]

Re: C3 Half shaft flanges hitting

I know adding weight at the rear will solve the half shaft bind but just don't understand why it wasn't binding/hitting when I removed all the weight during disassembly. I'll load it up and get the rear stabilizer connected and shocks if possible and see if that'll ge me enough to move ahead until the body drop.

Tom -

Connecting the rear stabilizer bar won't do anything, but getting the shocks connected might; original rear shocks performed the rebound limiting function (which was only important when "getting air"), but many replacements are slightly longer in rebound than the originals.

[Duke W.]

Re: C3 Half shaft flanges hitting

Like John says, rear shock extension is what limits rebound travel. Connect the shocks and see what happens.

Duke

[Joseph K.]

Re: C3 Half shaft flanges hitting

Here is a picture of the area. As you will see the wheels are not on and shafts turned without a problem. Compare to your car to see what the difference is. Joe