I've got an 03 LTZ with 120,000 miles and for the last several weeks I have been getting a louder and louder rumbling sound that's really noticeable once you hit about 35mph. It reminds me of loud tires. However, the tires aren't the source of the noise here. I jacked up the back end today and got underneath hoping to find a bad u joint or something easy but no such luck. When I turn the driveshaft even slowly by hand, I get what sounds like a dry bearing squeaking that seems to be coming from the transfer case. It's a constant squeak, not the on and off chirp that a universal joint would give. To answer the obvious questions, I personally changed the transfer case oil at 50,000 and about 100,000 miles and refilled both times with nothing but two bottles of the AutoTrak II blue fluid from the dealer. There are no leaks at all. When I checked it today, I pulled out the fill plug but couldn't quite reach oil with my finger but I had the back end jacked up high so I'd expect that. I loosened the drain plug and oil started to seep out. The transfer case seems to function properly. Is there a bearing that tends to go bad? I like to do as many jobs as I can myself, but a transfer case removal is not going to happen with my garage setup. Thanks for any insight. Also forgot to mention that the noise is the same in both two wheel or 4 wheel drive.
Last edited: