Trailing arm shims (late 70)

[John Fulton]

I am ready to reinstall my rebuilt trailing arm assemblies. When I removed them I looked for the cotter pin for the shims, but there were none. After being assured that the cotter pins were present in late 70 cars I went back and looked again and sure enough I found the holes. Based on the position of the holes I can conclude that the only purpose of the cotter pin is to go through the "rear of the shims" to help hold them in position? Some shims have slots and others holes, do the slots just fit onto the cotter pin as well? Lastly what is the correct direction to insert the cotter pin, towards the inside or towards the outside and are both ends bent or just one, if one which one?

Thanks.

[Terry M.]

Re: Trailing arm shims (late 70)

John,

Here is a place where the 1970-1972 Technical Information Manual & Judging Guide (TIM&JG) will help you. See page 108 & 109 of the Third edition. The same info is in the second edition as well, but may be on different pages.

Unless your 1970 is in the last 500 or so 1970 Corvettes there is no cotter pin. There are two styles of shims. In the last 500 1970 Corvettes the styles of shims are mixed, but the cotter pin was not used until the last 500 cars. Then, of course, it was used for 1971 and 1972 build.

Before everyone looks at their Assembly Instruction Manuals and tells me that the cotter pin shows up in both the 1969 and 1970 AIM - let me assure you that in spite of what the AIM shows the cotter pin did not appear in production until very late in 1970 model year. The hole was in the frame for all that time, but the cotter pin was not used until late 1970.

Terry

[John Fulton]

Re: Trailing arm shims (late 70)

I Love this board! Thanks, it was not in the last 500, its 10365, May 22. Tha explains why no pins!!!Thanks Terry

[Gary Schisler]

Re: Trailing arm shims (late 70)

As an added note, putting in stainless steel shims, with the cotter pin holes, is a very good way to go regardless of the year of purchase, unless of course originality is your concern. I put in these SS shims with the cotter pins when I redid the suspension on my 66. If I ever want to show the car, it is an easy one hour fix, with no realignment necessary. Sometimes I do things that are better than the factory at the time. Another example is the improved locking-style engine mounts.

[Joe L.]

Re: Trailing arm shims (late 70)

Terry----

I can attest to the fact that 69s didn't have the cotter pins. My original owner 69, built mid-September 1969, NEVER had any cotter pins from day one. In fact, my car had a "mix" of alignment shims; both the slotted and non-slotted. How do I know this? In the old days, whenever I would take my car to the dealership for any warranty work or other work which I couldn't perform(essentially just alignments), I would ALWAYS hover over the mechanic performing the work and watch them closely. I was one of the few customers that the dealership would allow to do this. In fact, there were only 3 mechanics that I would allow to work on my car: Gene West, "Red" Jones, and Ron Sterbanks.

Ron Sterbanks is the service manager there now. When I took my at-the-time brand new 1992 in for warranty work(opti-spark replacement), Ron remembered and told me that I could still provide oversight if I wanted to. He also "roped-off" my car in the service bay at the end of the work day since it took several days to get the parts. Ron says that I'm a service manager's worst nightmare, but he understands me. By the way, when I took the 92 in for this service, I had previously purchased all of the special tools from Kent-Moore necessary for the Opti-Spark replacement, figuring that the dealership wouldn't have them yet for the then-new LT1, Gen II engine. I put them in the front seat of the car and I told Ron that the mechanics were to use them and not some make-do tools. Ron laughed and said that that was the first time in his 35 year carreer that he had ever had that happen. But, he said, if it was ever going to happen, it could only have happened with me.

[John Fulton]

Re: Trailing arm shims (late 70)

I have the mixture of slotted and non-slotted as well. The only markings I can find on them is a V stamped on the thickest ones.

[Jack H.]

A Word From Our Sponsor

I appreciate your thanking Terry for his input/advice. It takes time for NCRS folks to get active and give feedback on this board. I'm sure our senior judges and National Team Leaders like Terry appreciate the feedback they get from inquiries on the NDB.

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[John Fulton, 29200]

Re: A Word From Our Sponsor

I understand the comment-I have two of them (70), one for my garage and one for bedside reading. Also have them for 65, 66, and 69. Sometimes this board makes me lazy and I dont go and do the research as I should before asking. But fair comment.