Well I went off roading out in barstow which is desert with whoops and is more high speed stuff but I threw it in 4x4 and blazed down some trails. Did a couple donuts and went through a small puddle. I didn't want to ruin my baby. Anyway now my trucks has a weird whining noise coming from somewhere. I can only hear it with the windows up and it almost sounds like I have gnarly off road tires humming down the street. When I put on the brakes it sounds exactly like mud terrains do. Like It sounds like I have mud tires. It can't be the tires though. When I turn there isn't any difference in sound or shutter. However in the desert doing donuts, there was a shutter under acceleration almost like axle wrap or leaf springs waving. I dont know if that was the leafs or the rear end shuddering. It doesn't shudder under normal driving conditions on the street. The noise is speed sensitive though. Any ideas?

 

Sounds very much like my pinion bearings did the 4 times that they went out. The service tech couldnt hear it until it got loud enough to crater the bearing races.

 

Have you washed out all the sand and crap that might be on the backside of your wheels? ...could cause that issue. Worst case scenario you could have push your truck too hard during those donuts and put alot of load on the carrier and pinion bearings in which case they will get worse and need replacing.

 

You were likely getting axle hop with the shudder. Are you sure you didn't have this noise prior and just happen to notice it after since you were "lookin" for problems since you ran it hard? Lots of people notice stuff after certain times because they are looking for problems rather than just noticing it on their own on just another driving day.
I would check your u-joints before getting all spooked out about before thinking of ring/pinion issue's. Gotta hold both sides of the u-joint to see if has any play.

 

I'd check to see that you don't have a lot of dirt/gravel packed up in your brakes first

Pull the wheels and remove the pads, good chance the backside are loaded

 

Agree - pull the pads and check for sand/grit/dirt. That stuff will make some noise, but will also score your rotors.

 

im pretty sure sand and grit on the pads would make squeiling noises, not a "mud tire" sound.. im going with dirty dog here

 

Front wheel bearings failing will make that noise too.

 

How ironic its after off roading though. I know it didn't have it before because its noticeable. I am going to pump out the fluids with one of those marine pumps used to pump out engine oil and replace it with some royal and the additives. I checked the oil and it is all burnt. Also, the truck really isn't that dirty. not nearly enough to get into brakes and all that.

 

If your going to drain the gear oil you should pop the cover and inspect the diff. for damage. Just a putting fresh oil in will not help a thing.