I need to replace the transmission in an '03 LeSabre.....what years will work?

2000-2005 LeSabre
2000-2005 Bonneville (except GXP)

At my local junkyard the cross reference stated that only the 03 LeSabre and the 03 Bonneville would work?? And they asked me which gear ratio it had (2.85 or 3.05) what is the difference in that..... how do you find out which it has? Would they be interchangeable?

https://www.gmforum.com/buick-172/cv...-ratio-305959/

also i remember when i was asking about it because mine has the weird 3.05 what would have to be done to use the 4 or 5 to one more common one. one of the trusted members here told me you can just change the diff housing. i ended up finding someone to rebuild it for 1000 which is a hundred times better option as the JY transmissions always fail in a few months or less, they dont like sitting.

I dont have $1000 AND I'm driving an Oldsmobile now that I put a JY Tranny in 4 years ago and its working greatly.

Hmmm yea forgot about gear ratio. The computer might throw ya an error if it detects something funny so might want to stick to 03. I do know that if you were to want a different gear ratio that was offered on the 4t65e, it is an easy swap. Just don't remember if that involves any reprogramming.

Edit: also to answer the 2.85/3.05 question, from my experience the N/A has 3.05 (like my old Bonneville SE) and supercharged has 2.85 (like the Bonneville SSEi). More than likely you have the 3.05.

the standard se and ssei have the 285 only the middle trim na 3800 like my sse get the 305.

your jy trans experience is not typical

Maybe that was so for the pre-2000 body style. My 2003 SE was factory with 305

the point is you have to look at the codes and then you can be sure. on yours and the donors