5th gear that is. 2009 H3 Adventure with the 3.7L engine, 5 speed manual and approx. 65,000 miles. It's been pretty much trouble free and the only visits to the GMC Dealer since I got it a bit over 2 years ago have been for routine maintenance. Just had the original Bridgestone Dueler A/T's replaced with Goodyear Wrangler Duratrac's of the exact same size. Took a trip to VT last week, about 600 miles round trip, and by the time we were halfway home there was a prominent "gear" sound when under power in 5th gear. None of the other gears exhibit any noise other than normal operating sound whatsoever.

Has anyone ever experienced this or heard of something similar on an H3 forum? Thanks in advance for any suggestions...

 

Guys, just looking for any advice, educated or not. My gut is telling me that it's a bearing issue with the 5th gear pair, but would hate to pull the tranny to have it rebuilt or core swapped only to find it was something else. Some generic Google searches yielded a variety of suggestions, many of which were center diff related, but don't see how it could be that when this sound is only present in 5th gear.

Thoughts?

 

It could be a bearing problem, but that sound would be evident in other gears
I would ask what speed you are traveling and at what RPM.
I have an 07, 5 speed and if I upshift to 5th at too slow a speed and a low MPH the trans will let me know that I am in a too tall of a gear for that speed.
You may have a bad synchro and it is giving trouble in only that gear.

I now change my trans fluid every 15,000 mi, just to keep all the trans internals shifting smoothly.
I had trouble getting into third gear and my new maintenance schedule seems to have solved my problem

How often do you change your gear oil ?
My two cents

 

Thanks for the input sir... and I liked the trans/diff fluids idea so much that I scheduled a visit at the GMC dealer tomorrow morning. Shouldn't take more than an hour, and worst case scenario is that I cross that off the list of possible causes.

If it doesn't solve the problem I'm thinking that it has to be the tranny... can't imagine any circumstance where the transfer case wouldn't be making the same sound across the entire range of gears. The flip side is that I also can't think of what set of conditions in the tranny would cause this noise in only one gear.