Trailing Arm Shims
Thread Starter
Instructor
Joined: Apr 2017
Posts: 205
Likes: 4
Trailing Arm Shims
Just finished pulling my t-arms off my 75 - along with strut rods, and half shafts.....
I pulled the left t-arm first and I thought that I was careful to note the shims used inside and outside of the arm. Then I pulled the right side and did the same thing. But right away I noticed that on the right the bigger bundle of shims was on the inside and the small bundle on the outside - which is opposite of what the left side was (larger bundle outside, smaller bundle inside).
SOOOO, I'm wondering if I messed up the left side markings.
Is it normal for the shim bundles to opposing (large bundle vs small bundle from left to right side)????
I pulled the left t-arm first and I thought that I was careful to note the shims used inside and outside of the arm. Then I pulled the right side and did the same thing. But right away I noticed that on the right the bigger bundle of shims was on the inside and the small bundle on the outside - which is opposite of what the left side was (larger bundle outside, smaller bundle inside).
SOOOO, I'm wondering if I messed up the left side markings.
Is it normal for the shim bundles to opposing (large bundle vs small bundle from left to right side)????
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,335
From: North of Toronto - Ontario
The set the toe on the rear so in theory there should be little or no correlation from side to the other side unless the frame and trailing arms were perfectly straight / aligned. In a perfect world I guess they would be the same but these were far from perfect even when new 
M
M
Racer
Joined: Feb 2012
Posts: 421
Likes: 27
From: Harrisburg PA
Just did this job on my 77 this spring...didn't seem to be any rhyme or reason to the shimpacks when I removed mine.
Honestly,, though, I could not get the "matching" shimpacks back in because the new bushing was brand new/stiff (old one was vert deteriorated/rusted).
I just tried to get them "close enough" to what was in there, and drove it to an alignment shop, gave them the leftover shims from the kit, and had them set up the toe properly...
Make sure you talk to the folks and find a shop that can do it...the first couple i tried working with/talked to were like "we can try it"...wasn't comfortable with that. Found a shop that had done multiples of them on these cars...
Honestly,, though, I could not get the "matching" shimpacks back in because the new bushing was brand new/stiff (old one was vert deteriorated/rusted).
I just tried to get them "close enough" to what was in there, and drove it to an alignment shop, gave them the leftover shims from the kit, and had them set up the toe properly...
Make sure you talk to the folks and find a shop that can do it...the first couple i tried working with/talked to were like "we can try it"...wasn't comfortable with that. Found a shop that had done multiples of them on these cars...
Le Mans Master
Joined: Aug 2005
Posts: 6,539
Likes: 1,972
From: Temple Terrace Florida
Just put the same number and thickness of shims on both sides of the bushing and drive to your alignment shop. I use stainless steel shims. I insert the thinnest shim first and hammer the thicker shim in last. As others have mentioned, find a shop that is comfortable with the IRS setup. Ask around your local Corvette clubs for referrals. Jerry
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
Just finished pulling my t-arms off my 75 - along with strut rods, and half shafts.....
I pulled the left t-arm first and I thought that I was careful to note the shims used inside and outside of the arm. Then I pulled the right side and did the same thing. But right away I noticed that on the right the bigger bundle of shims was on the inside and the small bundle on the outside - which is opposite of what the left side was (larger bundle outside, smaller bundle inside).
SOOOO, I'm wondering if I messed up the left side markings.
Is it normal for the shim bundles to opposing (large bundle vs small bundle from left to right side)????
I pulled the left t-arm first and I thought that I was careful to note the shims used inside and outside of the arm. Then I pulled the right side and did the same thing. But right away I noticed that on the right the bigger bundle of shims was on the inside and the small bundle on the outside - which is opposite of what the left side was (larger bundle outside, smaller bundle inside).
SOOOO, I'm wondering if I messed up the left side markings.
Is it normal for the shim bundles to opposing (large bundle vs small bundle from left to right side)????
