Let me start of by saying I've had some great tips off this forum repairing and maintanance - For that I thank you all..!!!!

THE QUESTION I HAVE : Are 4L60E Transmissions in Hummer H3 all the same for each build year?

- The reason I ask is because my 2008 Hummer H3 had a huge fail in the new radiator. This resulted in me driving around with cooling liquid mixing up with transmission oil and taking out my 3rd and 4th gear.
- Took it to a mechanic who took it apart and concluded there was too much damage.
- Bought a used but tested transmission out of a 2009 Hummer H3.
- Got installed by the mechanic and tested it out.
- Shifts just fine into Reverse, into Drive ..... goes from first gear into second but does not want to shift to 3rd or 4th
- Had the pan dropped and noticed a big difference between the original transmission and the replacement.

Could this possibly be the problem? Diffirent year H3 's transmissions are not compatible ??
I have replaced my TCM and had it programmed to my VIN
I have replaced the shift selenoids
Changed out the transmission fluid and filter
But all has not resulted in any change - still no 3rd or 4th gear.

I hope anyone can help make sense of this problem I'm having. This is my third Hummer H3 - I love these vehicles!

Best Regards,

Bastian

original transmission out of the 2008 H3

replacement transmission out of the 2009 H3

 

Used but tested by who/what/how? How many miles? Failure of 3 and lock up (3 to 4) is common after wearing out.

Used is used, it may need a rebuild. No 3rd or 4th gear: “3-4” clutches are worn out: Needs to be removed and rebuilt. The car is safe to drive (in 2) until you can get it fixed.

As far as I knew all H3 Auto Trans are the same, but 2006/7 are controlled by the PCM, 2008+ use a TCM.

 

I'd look for a tag on the 2009 transmission that shows the part number. Lots of 4L60e transmissions out there.

 

"- Bought a used but tested transmission out of a 2009 Hummer H3."


Why would anyone do this? Serious gamble. To what? Save $1500 maybe?

Get your old one rebuilt and kick the "new" one to the curb.

Or better yet, get a 6L80E from True blue.

 

I just replaced mine as well with I don’t know 4l60e transmission
the shifting is OK but after 50 miles there is a weird sound coming from the engine or transmission. also engine light
I don’t know.
See the video

 

If you have the "Check Engine Light" (CEL) then scan it and write down the code(s). Then start your own Thread in the H3 section to ask about your problem, include the code(s) with your video... instead of thread jacking this member's thread.

 

Clarification for future readers. The Auto Trans for H3 2006 - 2010 with the I5 engines are all the same. That is the short statement I made earlier, but there is more to it. For those assumption makers that stumble on this thread........

The AT for all 2008-2010 Alpha (V8s) are the same.

The ATs for the I5 have a different Bell Housing and Torque Converter that those used on the Alpha V8s. In other words, so long as you are talking I5 H3s, all ATs should be the same. All Alpha V8s should be the same. I5 ATs do not directly fit any Alpha H3s unless the Bell Housing and TQ Converters are changed as well.

 

 

Any compatibility issues with this proposal?

 

A chit ton of issues, different lengths, output shaft, new custom drive shafts, cross members and adapter, electronics, extensive tuning and about $9-10K+ if you do it yourself. The TBM package for an I5 to 6L80 is $6,625 + tax, does not include install, trans lines, cooler, drive shafts, fluid or tuning tweaks if needed.

Since you can build a 4L60E to take 1000 HP (extreme example, but true), I will be building what I have to absolute bullet proof and save my cabbage for gas and beer. Might be next winter's mod.