Mickey1

Hi names mike, I don't think I'm on the rite link here but have a question about a 4l60e tranny of mine... I have a 04 Chevy avalanch that lost all forward gears and thought I was mechanically inclined to swap with another. I messed up on first one but would like to try again. I bought a, I'm guessing older 4l60e BC of the bell housing and tail shaft hell the whole length was shorter the my original so my question is will the tranny I bought work or fit on my truck? I'm not sure what year or type of vehicle the Tran I bought came out of but I do kno it has 4l60e on the side of it. The one I just bought has the complete bell housing opposed to half like 4l60 so i m thinking it's around 1999 year. Can a 99 4l60e work in a 04 5.3

mrvedit

There are two mechanically incompatible versions of the 4L60E.
The older "LT" style has a 298mm input shaft.
The new "LS" style has a completely different 300mm input shaft and a deeper bell housing.
All LS-style 4L60E have the detachable bell housing and the bell housing has mounting hole at the top in the 12 O'Clock position.

All LS engine vehicles (other than the C5 Vette) use the LS-style 4L60E.
Since I believe your '04 Chevy has an LS engine, it would take the new style trans.

So, if the '99 trans bellhousing has a hole in the 12 O'Clock position, it should be OK, if not it is unlikely to work. To be sure, this thread has pictures and more info:

https://ls1tech.com/forums/automatic...hangeable.html