Rear Wheel Alignment

[Ray C.]

I need an education!

I have researched the archives, but could not locate the information I am looking for. I am working with a shop that has modern alignment equipment, but has never aligned a Corvette. The computer-controlled equipment has all the specifications need to align the 65 Corvette. I replaced the shims exactly as removed prior to body drop. My question is: What is the correct procedure for removing the trailing arm bolts and shims with the body on the car? How can I determine the thickness of shims to use after the measurements have been taken or is this a trial and error procedure? Can degrees and minutes (computer data) be converted to shim thickness?

Thanks for any help!
Ray

[Craig S.]

Re: Rear Wheel Alignment

Ray - to do this correctly, you really need to use the newer style shims with slots, and let the alignment shop perform the alignment. Then, if you wish, you can loosen the bolts, measure and replace with like 2 hole shims, and tighten, with the car loaded on it's wheels. Most folks avoid the old style shims, but I do understand your motives, I have a set for my 67 right now. As far as trying to compute the required shims, I would say forget it, way too many variables in the frame etc. It's trial and error to get the toe correct and in specification on the alignment machine...Craig

[Ray C.]

Re: Rear Wheel Alignment

Thanks! Craig

Craig, even if I chose to use the slotted shims, what would be the correct procedure to remove the original shims and bolt. I have the bolt 3/4 of the way out and I stopped. There seemed to be pressure on the bolt. I am just completing a frame off and the bolts came out and went in very freely during the restoration. The 65 shop manual states to remove bolt and shims, adjust from the inside until correct setting and then fill the outside space with the correct shims. Do not over shim. Is there any thing special that I need to do before removing the bolt?

Thanks for the response and all your help!
Ray

[Craig S.]

Re: Rear Wheel Alignment

Ray - come to think of it, this is probably one of the issues with using the 2 hole shims. I have always pulled these bolts after the rear spring, halfshafts, etc were removed. Maybe someone that has actually dealt with this on an assebled car can comment, I don;t want to lead you astray....Craig

[Gene M.]

Re: Rear Wheel Alignment

Ray if you pull that bolt out, you will have a hell of a time fighting the spring loading trying to put it back in. There is not enough room to follow the bolt out with a pin on the outside to keep the trail arm in position. I've done it by shimming top and bottom on the trail arm and clamping the whole thing so it does not move. You need to tear down and reclamp this set up for every try at shim spacing. I do not trust the non original sloted shims nor are the correct.
I go to an alignment shop that knows the old vettes and can tell from the readings just how much to shift the shims. (But I must say that I attempt to pre set them when the frame and body are apart.) Then I go back and he rechecks it. Haven't had to recheck it a second time yet, knock on wood.