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Dumb question, but im gonna ask anyways. So i took off the rear trailing arm to replace the bushing and rear bearings. Well actually my son took it apart for me. This was months ago and i just realized he didnt mark the shims. He taped/grouped them together, but didnt mark which side of the trailing arm bushing they were installed on. So im over here guessing now. One group of shims is .410 thousandths thick and the other is .380 thousandths thick. I have an idea which side goes where, but not 100% sure. My question is will that .03" make that much of a difference when putting it back together? Not really wanting to pay for another alignment. Thanks for any advice in advance.
Dumb question, but im gonna ask anyways. So i took off the rear trailing arm to replace the bushing and rear bearings. Well actually my son took it apart for me. This was months ago and i just realized he didnt mark the shims. He taped/grouped them together, but didnt mark which side of the trailing arm bushing they were installed on. So im over here guessing now. One group of shims is .410 thousandths thick and the other is .380 thousandths thick. I have an idea which side goes where, but not 100% sure. My question is will that .03" make that much of a difference when putting it back together? Not really wanting to pay for another alignment. Thanks for any advice in advance.
This will change the wheel angle ~ 0.115089 degrees. which is 0.867746926647315456/16th.
So I wouldn't worry about the change. But the bearing replacement might make a difference depending on how bad they were.
But check the alignment your self. Its easy to take measurements.
First step for a quick check is the rear wheels vs the front axle.
Measure the wheel angle vs the front axle. In the example both wheels measure 9mm. Red line is a laser pointer.
Here is my DIY Alignment procedure to read everything.
Last edited by cagotzmann; Jan 28, 2026 at 10:19 AM.
So that wouldnt make much difference huh? The bearing on that side (drivers) wasn't that bad. Curious, how did you come up with those calculations and difference in degree estimate?
not sure if your alignment shop offers but i do the 1 year unlimited alignment (Belle Tire) when i work on suspension and after every job have it aligned. Tips-
- make sure you have a trusted guy who knows what they are doing
- get SS shim package so they can dial it in. They will not have any for the rear, and the fronts i just use standard ones and shape as needed.
- once you find a guy tip well.
- get printout before and after
- i use factory rest specs on my 79 no issues.(pics)
- some may recommend another custom alignment but depends on usage.
- measure your end play in the axles. I was very surprised how that improved handling when tossing around.
- good advice/ replies
So that wouldnt make much difference huh? The bearing on that side (drivers) wasn't that bad. Curious, how did you come up with those calculations and difference in degree estimate?
Have you installed the Trailing arm yet ?, When I have changed them to a different brand, the original shims never fit the same usually required less shims.
Measure the length of the Trailing arms from center of the bolt to the center of the bearing. When adjusting shims calculate and angle change.
But I have a spreadsheet that I created to measure how much I what to move the wheel. In my example diagram if I want to move the wheel from 9mm to 10mm, which means a 1mm change, it calculates the shim thickness to move from one side to the other.
As far as effect less than 1/16th total toe in. Rear specs are total toe 1/8th .
but the thrust angle should be ~ 0 degree's. Just measure left vs right side, they should be within 1-2mm and 2mm the max.
With new bearings in place, just measure left vs right. If within 1-2mm then drive it and see how it feels.
Or find a garage that offers free alignment checks where they do the measurements to upsell a service, deny the service and see if they will show you a printout.
Last edited by cagotzmann; Jan 28, 2026 at 10:45 AM.
If you replaced the bushings then they are going to be a different thickness than the original ones and the shims will not be the same
I made sure that the new bushings were the same exact width as the old ones i took out. The old ones measured 2.23" from outer washer to outer washer. The new ones were installed exactly the same.
When you do take your Corvette down to get the four-wheel alignment be sure to take a bag or two of the Shims made from Stainless Steel. This will make it easier for the alignment tech to set it up easily. The shims are available at many Corvette suppliers in both steel and stainless steel. I bought 2 bags of the shims and had some left over when we were done.
I found a shop who had a alignment tech who "liked" Corvettes. He spent many hours getting my alignment "perfect". He started by removing every shim in the vehicle and started over. The car never drove so well until after he was finished. Having spent most of the evening there working on my C3 I tipped the tech very generously.
Part of the alignment process included re-centering the differential according to the tech. Once the drive line was centered then the rest of the car would be aligned.
Rear Trailing Arm Shims
