InsaneDomestics

iTrader: (28)

I've searched google and came up with multiple answers but none that I'm 100% comfortable with.
So my questions is this... I've got a 2003 Sierra with a bad trans. I know all the 4l60e transmissions will bolt up but are they all the same internally?
I've found some answers saying the 99-02 are the different than 03+ so I'm wondering if I need to find a 2003 specifically or if 03+ will work. I found an 04 that was pulled from a Tahoe for a reasonable price but I don't want to get it if it's not going to work.

mrvedit

Any '98-'07 4L60E/4L65E/4L70E from an LS-engine donor 2WD vehicle (except C5 Vette) will have a 300mm input shaft and work perfectly. The '03 does have a few strengthen parts (e. g. heat treated sunshell) and therefore later years are better.
An '08 is probably OK, but '09+ are electrically incompatible.
A '04 from another vehicle would be perfect.

InsaneDomestics

iTrader: (28)

Well the 04 I bought was no good either. So another question... will one from a v6 work or what is different about them?
Reason I ask is because I've got a friend that has one laying around and he may just let me have it.

mrvedit

If it has the 300mm input shaft, indicated by a bolt hole at 12 O'Clock on the bell housing, you are good to go.
What was wrong with the '04?

InsaneDomestics

iTrader: (28)

The same crap as the other one. It shifts into 2nd just fine and I feel the shift into 3rd but it just revs. I took it to have it scanned and there isn't a single code, engine or trans. So I assume it's those pesky 3-4 clutches.