Drum brakes vs wheel bearings?

My 2017 TRDOR (14k miles) manual is making a very very light grinding noise. It is almost to faint to hear. Rear sliding window must be open, and all other windows closed with radio off. Noise gradually starts +/- 35mph. Noise is not consistent with rpms, but is consistent with vehicle speed. Noise never gets loud no matter the speed, actually it could be my imagination....?

Anyways, how could I troubleshoot the noise to determine if it is an out of adjusted rear brake or a rear wheel bearing?

 

Put it in the air. If the brake is sticking it will be hard to turn the wheel. You can also pull the drums and have a look.

To check the bearing some times the noise will stop, if turning in one direction. Also when the truck is in the air or wheel lifts off the ground, see if there is any slop in the wheel. Grab the wheel with two hands (clock positions 12 and 6) and try to rock it back and forth. See if there is any play or movement. Shouldn’t be anything. You can also lift the wheel off the ground and take a long screw driver and touch it to the axle and put the butt end to your ear. Listen and see if you hear any noise that’s different from side to side. Just be careful not to touch any moving parts obviously.

 

Jack up the rear and rotate the wheels. May also need to remove the wheels and brake drum to determine where said noise is coming from.

 

After jacking up, will rotating the wheels by hand allow the noise to be heard, when driving the noise only appears at +/- 35mph.

As far as side to side noise while driving it doesn't appear to matter if I am turning or going straight.

 

Unless the bearing is really bad, you won’t get noise by turning the wheel by hand

 

You may have a small rock stuck between the front disc and the dust shield.

 

Sounds like it is coming from the rear. Only audible when rear window is open and all others shut. I mean, it could be completely normal. At this point I really don't know...

 

Bearing noise typically gets louder with speed (sounds like trans isn't shifting)...aren't you under B2B with a 17 and only 14k?

Matt

 

Truck is still under warranty. Problem is my dealer so far has not been very helpful (weeping diff issue for TRD OR), so I am guessing they will say this brake noise is "normal". And it may be normal to be honest. I really don't know. It isn't very noticeable.