My 15 XLT that i just picked up 3 weeks ago has a hum going down the road..... under 40....no noise.......40-70 a hum that sounds like tire noise. i swapped a set of wheels/tires that a buddy has that i know are quiet.....still there..... i can rotate the wheels by hand...no weird noises and no play..... Can the bearings be bad but still have no play?

 

yes, could be bearings. Could also be the IWE.

 

At speed with a hum, try turning left and right, usually a bearing will quiet down when turned into.

 

Bearings or ring and pinion in the rear end.

 

this morning i was able to do more testing..... at lower speeds i can still hear/feel the noise..... turning left does nothing really but turning right the noise is basically gone.

 

Ring and pinion is probably the culprit, the 18 that I traded had that issue.

 

You don’t say whether it is a 2x4 or a 4x4, but there is a distinct possibility that it is the right front wheel bearings. I had a SAAB that the right front wheel bearing failed on. It was barely noticeable for a while, but a long left turn would slightly increase the noise and a right turn would drop it to barely noticeable.

My ‘17 Lariat had bad 4X actuators and seals. It would have a slight grinding noise that came and went (53k miles). When the dealer finally realized I wasn’t going away because the IWEs weren’t engaging the front wheels on demand, they wound up replacing the actuators, seals, IWEs and wheel bearing hubs.

 

Sorry 15 xlt 4x4 it turned out to be the right front wheel bearing...... bought a new one today and when i took the old one off, it would grind and make noise when turning it.... the new one was perfectly quiet.
put the new one on and drove the truck..... nice and quiet now