I'm going to be replacingthe transmission in my '94 STS. Appears that it is a 4T80E transmission. Any reason a 4T80E transmission from any other year Seville or other Cadillac which has a 4T80E will not fit and work?

 

Check with the dealer or bone yard for which years and modleswill interchange.
A 2005 4t80e will not work properly with a 94 sts PCM.
The biggest difference i know of is the TCC changed around 2000.
There will be other changes through the years so you need to do your homework before you make the swap.

 

Thanks for the response. I have found out that the 94 STS 4T80E was a one year one year only STS tranny. Different wiring harness and various other items. Going to rebuild the one I have.