i have a 1975 corvette, we did a body off, 22000 miles at this time the drivers side front tire rubs on the fender lip when turning. took it to a shop for front and rear alignment, they saidrear is way out of line, but they could not fix it......i dont know what to do ...help brothers

thepapster

 

Does this shop normally do C3 alignments?
What on rear was out of line, toe or camber?
What about the front, what was out of line in the front?

 

Where, exactly, does the rub occur? Was it first noticed on the first drive after the resto? Did you change wheels and or tires as part of the resto?

Assuming the rub is at the lower front, with the wheels forward, count the number of number of steering wheel turns and partial turns are needed before contact. Repeat the exact number of turns/partial turns to the left and see where the passenger tire is relative to the fender lip.

Post pics of both sides.

 

Back a few years ago I was having the same issue with the front drivers side tire rubbing in hard turns. I replaced the bushings and other parts in the rear suspension and needed to get the car aligned. First I went to a few shops locally and spoke with their alignment technicians to see who would get to align my C3.

I ended up going to a NTW store that had a technician who claimed to "love older American cars". When I took the C3 to him he was surprised at the new parts and bushings that made his job easier. He took my C3 down and put it on his alignment machine. I had given him two packages of new stainless steel shims to use on my alignment. He did the most complete alignment of a car that I had ever witnessed. It took several hours and the boss was not happy, they check the alignments on cars as they go through and my car being there made others wait a bit longer than usual.

When done, the tech told me he started by removing all the shims and then "re-centered the Differential" before setting the alignment. Being a 4-wheel alignment he was able to get the alignment perfect but it took several hours for him to do the job. I tipped him (very) well and praised the alignment tech to his boss. The Corvette handled so much better after the alignment was completed.

A different shop had a guy that I heard saying to another employee that he hated old American cars. Be very careful just WHO you let work on your Corvette. There are some people I would not trust to add air to my tire let alone touch any mechanical systems.

 

If your car has ever been in a front-end accident or something like hitting a curb you might want to look at the rear mounting area of the lower A-arm. When I bought mine, I had a problem with the alignment and after having it "aligned" it still wasn't right. My right front tire would hit the lower part of the fender. When I had the wheels straight, I could see a difference between the placement of the front tires. The right front was further back than the left. I took it to a couple of frame people, and they could not find anything wrong. I replaced the lower A-arm which do not fix anything. I eventually put it on a lift and using tape measures and straight edges figured out that the rear mount of the A-arm was bent. It is bent from the factory, so it is difficult to see when it isn't correct but comparing left and right sides carefully showed me what was wrong with mine. Took it to a different frame guy and showed him exactly what was wrong and he corrected it. Problem was solved.

 

these corvette’s are a breed in itself.. first and most obvious make sure you have the right size tires on there… The 75 came with GR 70s that are equivalent to 225/70/15 or or 215/70/15 .. it is extremely important that all your front end and rear parts are in good working order… It is very hard to find a good mechanic to give a decent wheel alignment. I am very fortunate. .I am very fortunate. I have an old school Mechanic who did my alignment ( 82 yrs young) and did a perfect wheel alignment laser straight. It took him 4 hrs and I bought him a full set of shims .. not to many mechanics want to work on corvette’s let alone do a wheel alignment . There a dying breed wishing you good luck

 

When you put the body back on did you use the alignment holes under the door sills to center the car… if not you might want to check that first

 

curious, how do you recenter a diff ? I just had mine out for rebuild and there was zero movement once all three bolts are in going back in. Unless it's a different set up than my 81 and you can move it around before tighten up the bolts?

 

Yeah that was my question too. Not sure what bolts you are referring to but here's how the diff is located. Once the body is back on, those bolts are very much not easily accessible.

 

So I have questions ..
1. Do you have pictures of where it’s hitting
2. did it always rub or did you just notice it was rubbing
3.did you check that all the bolts are tight on the suspension
4. was the car ever in a front end collision
5. When you put the body back on did you center the car with the Holes under the door sills
I went through this whole scenario more then once

 

on my diff bolts I was referring to the bat wing bolts and front bushing bolt , you can't move that diff at all when the bolts are in , I think it's a war story that the alignment guy said he recentered the differential , not to mention it really is not a big deal aligning a vette if the rear shims are not all rotted , you set the camber with the eccentric bolts then move shims from one side of the trailering arm to the other if necessary to set the toe.

 

He hasn’t responded so he probably figured it out

 

took it to a alignment shop recommended by a corvette shop. they did the realignment , goes straight down the roared etc... but still slightly rubs when turning .only on the drivers side front lip`

 

So, you said you took the body off. Not certain if you meant that the car has 22,000 miles on it or you did it 22,000 miles ago.
And to re-ask someone else's question.
However, when the body went back down, did you use the alignment holes in the door sills?? Did your pins line up absolutely perfectly?

 

I already asked and he never responded