'99 2 door Tracker 4x4 auto 190,xxx miles. I've been hearing a slight hum from the rear of the truck for the past 2 weeks. It doesn't sound like a gear whine, trust me I know that sound! It doesn't change pitch with speed, but it does get louder. The weird thing is, when I step on the brakes it doesn't change, but when I pull up on the parking brake slightly it quiets down.  I'm thinking wheel bearing? Is there any way to diagnose that? Any thoughts on what it may be? I've got the weekend to mess with it, then I'm back to my 230 mile daily commute. Thanks in advance for any input!

I would jack up one side, remove the wheel then give the drum a spin while listening carefully.

If you hear something. try rotating the brake adjuster.  Loosening should quiet thing down. Tightening will cause the brake pad to drag,  If loosening does not stop the noise, the next step would be to remove the brake drum for a further inspection.

Repeat for the opposite side wheel.

This, of course, assumes that '99s have manual brake adjusters...

If it is a bad bearing, do a search for wheel bearing at Ack's FAQ (see link in signature).  Look at all three of the resulting links.

I hope that this helps!

Thanks! Not sure if the adjusters are manual or not. This is my first Tracker and the first time I'm messing with the rear brakes, so I guess I'll find out tomorrow when I dig into it. I need to change a bad wheel stud on the one side, so I'll be up inside the drums for a good look. I'm soooo hoping it's not a bearing! That's a great writeup on your site, but I don't think I have the means to tackle the job myself.

For a suspect wheel bearing find a quiet stretch of road and do a gentle left/right/left/right "sway" - what you're trying to do is rock the vehicle side~side - a defective wheel bearing will usually get louder when loaded & quieter when unloaded, so the left/right sway will alternately load each side allowing you to determine not only if there is a bad bearing, but which one it is.

Having said that - if there's a bad wheel bearing, I would change both - unless one side has experienced some sort of "trauma", both bearings will have traveleed a similar distance and be equally worn.

I am thinking you have more of a brake drag issue rather than a wheel bearing one. I had a similar noise and it turned out to be corrosion on the brake components that caused irregular wear. jack the rear end up and slowly spin the tire/wheel and listen/feel for a drag in specific areas of rotation.

Welp, opened everything up today and I think it is a bearing. The drivers side axle seems much harder to spin by hand than the passengers side and I do hear some groaning without the drums on. Brake wise everything seems OK other than having to chip off about 1/4" of rust build up from the drums. It actually seemed to creep onto the inner edge and build up enough that it was rubbing up against the backing plates on both sides. Also turns out I had more than one bad wheel stud, so I gotta run to the store to pick up new ones before I can put it all back together. Then to figure out what to do about the bearing. Any idea what a shop might charge?

Had to bite the bullet & take the trucklette to a mechanic today. It sucks not having the space or proper tools to do a job myself. Turns out that none of the parts houses around here carry the bearing retainer ring so they had to go to the local Chevy dealer parts counter for it. All totalled, $99 for the bearing, $29 for the retainer & 2 hrs labor at $65 per. Not to mention losing a days pay to bring it in. At least it's fixed and I can drive to work in the morning.