Rear Gear codes - 1978
Thread Starter
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Rear Gear codes - 1978
Does anybody have the codes for the rear gear on a 78 vette - I have my diff out and just want to verify the contents - I could also count the teeth on the ring and pinion I know, but it always good to know another bit of info.
Thread Starter
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: Rear Gear codes - 1978 (paul79)
Well I finally went back into my garage to look at the codes on the diff case.
The main reason i asked this question was that any codes on te bottom were difficult to read but it sure looked as iff there was 355 stamped on the bottom of the case. Well I would have been bummed if it turned out i had 3.55 gears instead of the 3.70 i thought i had. I still think there is something odd about whats on the bottom of the case 'cause it sure dont look like the codes above, in truth i really just cant read it.
instead i spun the ring gear around until i found the gm part number and the 37/10 notation (ring/pinion) which equate to the 3.70 that i expected to have in an l-82.
alls well that ends well
The main reason i asked this question was that any codes on te bottom were difficult to read but it sure looked as iff there was 355 stamped on the bottom of the case. Well I would have been bummed if it turned out i had 3.55 gears instead of the 3.70 i thought i had. I still think there is something odd about whats on the bottom of the case 'cause it sure dont look like the codes above, in truth i really just cant read it.
instead i spun the ring gear around until i found the gm part number and the 37/10 notation (ring/pinion) which equate to the 3.70 that i expected to have in an l-82.
alls well that ends well
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Le Mans Master
Joined: Sep 2000
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From: Westfield Indiana
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Re: Rear Gear codes - 1978 (paul79)
OK-3.08:1
OM-3.36:1
OH-3.55:1
OJ-3.70:1
OM-3.36:1
OH-3.55:1
OJ-3.70:1
BTW, I have also seen literature that states the rear was 3.73, not 3.70. Any ideas as to why? Not that the .03 would make much difference, but I'm curious as to why there would be an inconsistency in the lit that is out there.
Le Mans Master
Joined: Feb 2000
Posts: 7,032
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From: Newburgh NY
Re: Rear Gear codes - 1978 (sharklover)
The numbers are stamped (although sometimes not very deeply) into the bottom of the diff on the lower part of the housing. If you look up from the bottom (after removing the heat shield) it should be right in front of the lip where the pumpkin (cover) bolts on.
Thread Starter
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: Rear Gear codes - 1978 (sharklover)
.....I have also seen literature that states the rear was 3.73, not 3.70. Any ideas as to why? .......
Melting Slicks
Joined: Aug 2001
Posts: 2,043
Likes: 1
From: Elkhorn WI
Re: Rear Gear codes - 1978 (sharklover)
I am pretty sure the 3.70 (and the other 'vette only gears, 3.08,3.55,3.70,3.90,etc) needs a different carrier guys than the normal GM with the 3.73 due to the mount or the half-shaft setups we run in the vettes.....our carrier is 'special'....
[Modified by ylose, 10:22 AM 1/28/2002]
[Modified by ylose, 10:22 AM 1/28/2002]
