Drivetrain Moan

[legokcen]

This is a '97 Limited 2WD, w/ 42K. Recently, I've noticed a slight drivetrain moan while driving. It's not engine related as I can put in the N, and at engine idle, but still at speed, I'm still getting it. It seems to follow with speed. I recently changed the rear diff fluid and didn't get a change. I didn't get a lot of gunk out of it (at least nothing more than ordinary for rear diff fluid). I also checked and I don't have much play in the drive shaft or any U-joint issues.

Still drives smooth and well, just have a slight moan. I have to turn the radio off and the air down to really hear it, but it didn't sound normal.

Any ideas on what to check next. This weekend I was going to remove the wheels and check wheel bearings.

Thanks in advance.

 

[004Gunner]

That sounds like a wheel bearing to me. I just had a machine shop replace my driver side rear. Unfortunately the wheel bearings are not a DIY unless you have a shop press

 

[legokcen]

I've got access to a machine shop that a buddy of mine owns. Hopefully, it's something like the wheel bearing and not the rear diff. I'll check out the wheel bearings this weekend.

 

[legokcen]

I jacked the truck up and checked a few things today. The rear wheels when I spun them are making a repeating clicking noise as they spin. It's coming from the brake or hub, on both. Any ideas? The drivers side isn't spinning as easily as the passenger so I'm going to pull that apart and see if the bearing is an issue. I didn't get any sort of moan when spinning them by hand. I may put the truck up on 4 jack stands and run the tires with the engine to see if I get any sort of moan from the diff or drive shaft.

Anything else I should check?