Are these the correct trailing arm shims???

[Terry M.]

Re: Are these the correct trailing arm shims???

Mike------


Well, the change to the slotted shims happened late in the 1969 model year. In fact, my original owner, September, 1969 built convertible originally had a combination of shim types-----some of the "2 hole", some slotted. However, while there were cotter pin holes in the frame, no cotter pins were originally installed. Some (or, many) judges might regard the "2 hole" shims as the only correct type for any 1969. They're right for early 1969 but not correct for late 1969. So, when did the change occur? I'd say, it STARTED about the time my car was built (that's why mine had a mixture of shims). However, I believe that, either way, the outer hole for 1969 (and, maybe, early 1970) should be round and not oblong.

As far as what the purpose of the second hole is for the "2 hole" shims, all I can figure is that it was to make the shims installable either way OR there was some PRODUCTION-utilized function. It was certainly not for a cotter pin retainer since 1963-E1969 frames did not even have the cotter pin holes.

By the way, the late 1969 slotted shims were not the same as the 1970-82 slotted. The late 1969 shims were GM #3965192 through 3965195. These were also available in SERVICE until 1972 when they were replaced by the 1970-82 shims, GM #3983392 through 3983395. So, what was the difference between the two sets? The earlier set was 4-3/4" long and the latter was 4-1/2" long and the hole in the earlier shim was round while the hole in the latter was oblong. The oblong hole might have made it easier for cotter pin insertion.

Whether your 1969 was originally equipped with "2 hole" shims or slotted shims, I recommend the slotted type (for 1963-E69, too).

Joe
Your Fall of 1969 produced car must have had the slotted shims as a test or experiment. None of the original 1970s I have examined (but I will grant you I haven't seen them all) had the slotted shims until the last week of 1970 production in July of 1970. Perhaps there was some production reason they delayed their introduction, although I have figured they had a large stock of shims on hand.

[Joe L.]

Re: Are these the correct trailing arm shims???

Joe
Your Fall of 1969 produced car must have had the slotted shims as a test or experiment. None of the original 1970s I have examined (but I will grant you I haven't seen them all) had the slotted shims until the last week of 1970 production in July of 1970. Perhaps there was some production reason they delayed their introduction, although I have figured they had a large stock of shims on hand.

Terry------


I don't understand how it's possible to discern what type of shims are installed with the shims installed on the car. I did not find out what type were on mine until they were removed.