rearend

[djgj74]

I found these numbers on the web of my rearend L2161 and under that is 3726898 an din big letters GM and beside that is a T and I on the bottom any help would be cool. I have never seen the 10 bolts toward the cab always at the back of the pumpkin?

 

[old man dave]

It sounds like you have a late 50's-early 60's GM rear differential. They look like a Ford 9" but not nearly as strong. Pics would be nice.

 

[djgj74]

Rear end

Gonna try to post pics!

 

[djgj74]

Transmission, Rear End Question

 

[djgj74]

Rearend

Can someone help me on this not really for sure what to by parts for thanks.

 

[Dirtyrat]

I know the 50s pontiac & olds had very similar structural ribs on the snout of the differential.
But I dont have a casting number list to help you with.

 

[old man dave]

What vehicle is this setup installed in? My 1962 Impala has the same rearend with the upper arm and 2 lower trailing arms. It looks like someone cut off your trailing arm mounts and made a leaf spring suspension. The stud that is facing to the rear with nothing mounted is for a panhard bar.
NastyZ28.com has all the info to decode your differential.
Also the brake line should go behind the bracket not between the bracket and a moving part.

 

[djgj74]

Rearend

This is in a1950 Chevrolet truck I bought and yes someone has done some cutting on the back side.I have never seen one with the bolts on the front side are these good rear ends to use for everyday drive? Thanks guys for the help!!

 

[old lady's mad]

youd be better off all around to just get another axle out of something later model with redily available parts like an s10 or something depending on how wide you need it and big or little bolt pattern

 

[Dirtyrat]

youd be better off all around to just get another axle out of something later model with redily available parts like an s10 or something depending on how wide you need it and big or little bolt pattern

I'm not so sure that is the case, from what I have heard, these (if it is in fact a pontiac or olds from the 50s) were sought after as they were stronger than the chevys of the same era...

 

[old man dave]

If it is working now i would not change it just to have something newer. All GM cars from 1955 until 1964 used this type of differential so that tells me they cant be all bad. You can still buy rebuild parts and posi units for this setup. Remember that GM also used these with 409 cars.

 

[Dirtyrat]

If it is working now i would not change it just to have something newer. All GM cars from 1955 until 1964 used this type of differential so that tells me they cant be all bad. You can still buy rebuild parts and posi units for this setup. Remember that GM also used these with 409 cars.

I think 59-64 were the same (stronger 31 spline axles), whereas pre 59 was 29 spline (Chevy 8.2)?

I do know pontiac/olds was different design from the chevy and was not interchangeable internally.

 

[djgj74]

Rearend

Would there be more numbers? I'm not having any luck finding out anything with what I've got unless I'm not doing it right.

 

[old man dave]

Did you look on nastyz28.com. this site can tell you everything about this rearend.
I stand corrected they do not have this info. I just fully researched mine a few months ago and thought i used that site.I will keep looking and let you know what i find.

 

[old man dave]

Did a little research and found a site called 60impala.com. They have decoding for a 60 Chevrolet only but it does tell you what the numbers mean. The L2161 is the casting date that breaks down to December 21 1961. The 3726898 tells you it is a non posi. There is another set of numbers that are stamped in the case that will tell you gear ratio installed and the assembly date. These numbers are hard to see and can be found on the opposite side of the housing.

 

[djgj74]

Rear end

Thanks for the help on this I am going to look for the other number today after work. If u find anything else please post it.

 

[djgj74]

Rearend

I looked everywhere on the rearend and I couldn't find any more numbers not for sure where else to go? Any ideas thanks