Any ideas on a bearing growl in axle/transfer case area?

?02 Pontiac Montana with 90k. There is a bearing growl coming from the front end that is getting progressively worse. Starts in at around 30+ mph and gets louder with speed. It?s also a little worse when braking. Some vibration is felt through the floor & pedals. It’s not the clunk that is usually associated with back CV joints. The noise is slightly less when on a curve to the left. Noise is independent of engine or gear.

At first I figured it was a wheel bearing. In order to figure out which side it was coming from I put the car up on jack stands and spun the wheels in drive. However, when I did that it seemed like the sound isn’t coming from either wheel but more towards the middle of the car. My best guess is that it may be coming from the left side of the transfer case near where the left axle attaches. Is this a common area to have a problem, any suggestions what this could be?


It still could be the CV joint. They don’t necessarily just clunk. Sometimes they just howl.

I know a mechanic’s stethyscope will pin-point where the sound is coming from.


I actually wouldn’t rule out the wheel bearings. If you spin the wheels in drive you’ll be turning the transmission, and it will make noise - you’ll hear the gears and such spinning. Did you try spinning the wheels in neutral and jiggling to see if they have any play?

I would also look at the other 2 suggestions - if you’re sure you weren’t just hearing the transmission spin, then a stethoscope can go a long way. (Of course, I’ve never bought one - I just stick a piece of vacuum tube in one ear and fish around with the other - quick, cheap). And CV joints don’t necessarily go in the typical clunky sort of way.