GM Differential Cover Question

Questions about all other brand differentials.
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GM Differential Cover Question

Post by gsman » Sun Nov 19, 2006 2:52 pm


I have 1967 Buick GS 400. Currently a "peg-leg", I want to change to a 3:42 or 3:55 posi. My question is this: While checking the axle housing codes (which I still can't find - thought it would be located on the passenger side inward but it's probably outward - I'll scrub some more rust off :lol: ), I noticed a code on the differential gear cover. The numbers are 1376689. The numbers are stamped not raised. Can someone tell me what these numbers mean? Would the numbers help decode the inner workings of my differential?

Any ideas or comments would be appreciated.


Dave Cassel


cover numbers

Post by monzaz » Wed Nov 22, 2006 1:43 am

GSMan, sorry nothing but the GM part number for the cover it self.

How rusty are the tubes? OR how clean... someone might have already sanded the tubes and almost wiped them out.

You might have to go all the way aroung that tube and EVEN try the other side. There must be some thing there. S2 RA R1 ... something. Keep looking.

I think pontiac puts them on the back side of the tube instead of the front. Buick should be in the front.

Good luck. Have you opened the rear yet? the numbers will be on the edge of the ring gear if you keep spinning it and wipping with a rag.

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