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Driving H2 into remote places ( spare parts lost )
Hummer H2For those who like a little more gleam to their Hummer, the H2 offers a similar rugged look as the H1, but as a lower cost, and with more added features, making it almost a massive luxury SUV.
you remember in one of my posts I said someone added external cooler?
I was wrong it was the factory little cooler that you mentioned and it’s not cooling the transmission properly
there is a 15 mile 6% grade from Baker Ca to Vegas that stretch is nightmare for trucks,
it was 95 outside on Wednesday and my transmission temperature was 240 going up that hill.
its time to upgrade that.
See my reply to the guy about the shift lever bushing solution lol...
Nobody can keep a 4l****ty in a tahoe yall gotta be driving Mrs Daisy to keep one in an H2...
Shoulda had a 4l80 stock
Imho it shoulda had a 9.5 front diff and a 10.5 rear too... Probably 1.5" higher suspension, and then slightly larger tires to compensate the larger diffs lol (clearance is why they neutered it. And bean counters)
FWIW when you look at all the actual specs the h2 has the highest springrates if any GMT800/820 because the enormous body was so heavy, yet they outfitted it like a 1500hd because i guess they didnt expect anyone to pull with them?
What diameter bolt did you end up going with? I've got a couple metal lathes where I could turn something down to the right diameter. Think I'll go ahead and follow your lead on this, proactively eliminating that plastic bushing
Robert here is the measurement for the bolt I used for the shifter
Correct information on the forum is quite important. Relying on a Google search with AI is not usually accurate. The 4l60 have an RPO code of m30, the 4l65 has an RPO code of m32. Two different animals.
A lot of what's on the internet regarding this is wrong. So what follows is a picture of an early 2003 Hummer H2 label with the RPO codes....
As a general rule on these forums, if you don't know what you're talking about say so.... Like if you're taking a guess at it.
And regarding the external transmission cooler in front of the center of the radiator.... Yes, if I lived in a hot climate I would upgrade it. The bracket on bolts from the front, you can remove the cooler with the bracket attached..... Simply drill out the rivets holding it. I would find an aftermarket one the same height but wider.
Lol, I've seen your fabrication skills, should be a real piece of cake
Correct information on the forum is quite important. Relying on a Google search with AI is not usually accurate. The 4l60 have an RPO code of m30, the 4l65 has an RPO code of m32. Two different animals.
A lot of what's on the internet regarding this is wrong. So what follows is a picture of an early 2003 Hummer H2 label with the RPO codes....
As a general rule on these forums, if you don't know what you're talking about say so.... Like if you're taking a guess at it.
No I agree, my point is I fail to delineate between submodels of the 4l6xxxx transmissions. I believe there's a 4l70 or something as well before you take the training wheels off and graduate to something you wont have to spend $1500 rebuilding every year like its clutch maintenance...
Edit:
Again, not driving mrs Daisy...
4l80 or go big leagues and do either a stick or newer six speed auto or a ten speed out of a newer dodge or something like Nivlac was talking about...
The 4l80 is low hanging fruit
The stock trans is garbage in all of these 1500 gmt800/820 platform vehicles...
Even the 1500 manual is trash you gotta get the HD manual...
Last edited by Scope_Creep; Sep 21, 2025 at 07:25 PM.
Correct information on the forum is quite important. Relying on a Google search with AI is not usually accurate. The 4l60 have an RPO code of m30, the 4l65 has an RPO code of m32. Two different animals.
A lot of what's on the internet regarding this is wrong. So what follows is a picture of an early 2003 Hummer H2 label with the RPO codes....
As a general rule on these forums, if you don't know what you're talking about say so.... Like if you're taking a guess at it.
ah yes a whole 20ft/lb of torque rating difference in the two transmissions.
