Hummer H2 transfer case making grinding noise in 4WD, hoping it's not completely shot
Took the H2 out to the desert last weekend for the first time in months and when I engaged 4WD high the transfer case started making a grinding noise that definitely wasn't there before. Switched back to 2WD and the noise went away immediately, tried 4WD low and same grinding sound but less intense. The 4WD still works, the truck pulled through the sand without any issues, but that grinding noise is concerning and I don't want to use 4WD again until someone who knows these trucks takes a look. Could be low fluid in the transfer case, could be a stretched chain, could be the encoder motor not fully engaging, could be worse. I need an
Al Quoz Hummer expert repair shop that's familiar with the full time 4WD system on these trucks, they're getting rarer these days and not every mechanic understands the H2's specific transfer case setup. Dynostar seems to have experience with Hummers based on some forum discussions I've found. Anyone with an H2 had transfer case grinding specifically when 4WD is engaged but silent in 2WD, what did it turn out to be and was it rebuildable or did you need a whole new transfer case? I'm really hoping it's just a fluid change and maybe an encoder motor adjustment rather than internal damage, those transfer case rebuilds aren't cheap and finding a good used one for an H2 is getting harder as these trucks age. Also curious if anyone has switched to a heavier weight fluid in the transfer case to quiet down chain noise, or if that's just masking a problem that needs to be fixed properly.
