Welcome to HF.

Help with what?

Might be important to specify which Hummer year, model, miles, and recent work performed.

Otherwise, we got no idea what you are asking about.

So the answer is. Your transmission is broken?

 

it's a clutch pack issue, allot of the 4l60's have that issue and it won't shift out of 2nd, into 3rd or 4th....I have a friend who has the same trans as that of the h2 in a Tahoe and it does the same thing, no 3rd or 4th but all the other gears...its a cheap fix as in parts, but you have to pull the whole drive line out to repair......best of luck

 

Unless it is an H1, which means what you suggested is irrelevant.

If people asking questions can't bother to describe what vehicle they are asking about, ain't no point in volunteering guesses. Just sayin.

 

Your right if it's a h1, then disreguard it's a Allison trans, but h2 uses a gm 4l60 series trans and transfer, and they are notorious for killing clutch packs and loosing 3rd and 4th....just would be nice if people give info about said hummer and others wouldn't be a bunch of dicks when all some of us just want to be helpful to keep these beauties rollin or those whom don't know or are looking for a direction

 

Actually if it is an H2 or H1 it could be MANY different types of transmissions.

H1
6.2L Diesel TH400/3L80 3-speed
6.5L Diesel, 5.7L Vortec gasoline, 6.5L turbo Diesel 4L80E 4-speed
2006 Alpha ONLY Allison 1000 5-speed

H2
6.0 L V8 4L60E 4-speed (2002–2004),
6.0 L V8 4l65E 4-speed (2005-2007)
6.2 L V8 6L80E 6-speed (2008–09)

No one is being a dick, just like to have accurate information on HF.

 

Will running my Hummer h2 at idle with no transmission fluid damage my trany?

 

Hey. Will running my Hummer h2, 2003 at idle with no transmission fluid damage my trany?

 

Hey..... what does your question have to do with no shift 3er & 4 gear involving an unidentified mystery vehicle? So much so that you had to post in this thread twice?