Anyone know what the difference is between the 93-96 & 97 Rear Main Seal Retainer Housing? For some reason GM lists two different part numbers but I can't figure out what would be the difference between the two. I know they are all one-piece rear main seals so I was thinking that maybe it had something to do with the 97 being OBD-II but it can't be that because the 96 is OBD-II as well.

93-96: 14088556
97: 12554312

Any ideas?

 

I think the later one might be Teflon or something. There is no difference in size.

 

Hey shoebox, nice to see you're still around.

You're referring to the seal right? I'm talking about the actual housing.

 

I don't know what the real difference is in the housing. I can't recall anyone talking about it much. Never had a chance to compare the two side by side. Sorry I got off on the seal.

 

I think you're right about the difference being the seal itself! I was looking at the two different part numbers on Summit Racing and I noticed that when you buy the housing it comes with the seal already installed! And if you look at the picture for the #12554312 (97) you can actually see that housing has a #14088557 (93-96) part number stamped right on the housing.

https://www.summitracing.com/parts/nal-14088556

https://www.summitracing.com/parts/nal-12554312

So indeed it looks like the difference is just the seal itself and not the housing.

Thanks for the help shoebox.