Hi folks,
I've been chasing down some hub/bearing noises for a while now. Here's what I know: 1) the sound is a sort of "whomp whomp whomp" that is loudest at 30-40mph, not noticeable at highway speed (may just be covered by engine noise). 2) Jacked up and turned both front hubs by hand, no thumping or play, so I don't suspect the main wheel bearings. 3) The sound gets much much fainter when the hubs are locked. 4) When I grab the u-joints and try to turn the front axle shafts by hand, they stick (turn easily for 1/4-1/2 turn, then get really hard to turn). This happens on both sides.

Any ideas?

Thanks,
Jack

 

it may be a u jonit in the axle if it is hard to turn. but most of the time whomp is a wheel bearing.

 

What's the best way to check the u joints?

I thought it might be whatever bearing carries the end of the axle shaft in the hub, allowing it to spin independently of the wheel when the hubs are in auto mode. I forget what this bearing is called, but would it make sense then that the noise is much quieter when the hubs are locked?

Thanks,
Jack

 

Needle bearing for the axle stub.

You better leave that hub locked until you can get it apart to inspect and lube or repair!

Things can get expensive in a hurry if you eat up a stub axle.

The bearing itself is only around $10, and available separately, but DON'T let it go!

See: http://www.guzzle7pt3.com/nblube.php

Pop

 

Oh boy, thanks Pop. I hope the axle is okay, I'll be back once I get it all apart.