Extremely wierd screeching noise!

[ShawTheTJ]

I have an extremely wierd noise to try to diagnose, hopefully some of you have experienced it and may help.

So the noise is a pretty high pitched screeching/grinding noise, definitely metal on metal, starts above 5ish mph and speeds up with the jeep, so it's definitely a rotating noise. The wierdest part is that it goes away after the jeep warms up and rolls around for about 10 minutes. The noise started after a snow wheeling trip in 3+ feet of snow, it may not be related but may help someone diagnose it.

What I've done so far: I replaced the passenger side hub as I thought it was the source of the noise, but that didn't help. I replaced both the pads and the rotors on both sides with no improvement. The U joints aren't or don't seem to be the issue, as they are in great condition and don't bind or click or anything of the sort. The noise also doesn't increase when I turn. The rear brake shoes and drums have good pad life and no wierd wear.

I've been under the jeep multiple times looking for the noise to no avail. At this point I'm just curious as to what the heck it is!

 

[qslim]

Does the noise change as you turn the wheel/brake/accelerate? Is it related to engine speed or vehicle speed?

Can you put it up on jack stands & put it in gear?

 

[ShawTheTJ]

Does the noise change as you turn the wheel/brake/accelerate? Is it related to engine speed or vehicle speed?

Can you put it up on jack stands & put it in gear?

The noise only changes with acceleration, vehicle speed not engine speed. I put it up on a lift and put it through the gears, it was dead silent. Like I said, super wierd!

 

[OldGloryLJ]

The noise only changes with acceleration, vehicle speed not engine speed. I put it up on a lift and put it through the gears, it was dead silent. Like I said, super wierd!

Did you apply brake pressure at the same time as gas? Sometimes you need to add a load to simulate driving. If I had to guess I would say check the rear pinion bearing.

 

[ShawTheTJ]

Did you apply brake pressure at the same time as gas? Sometimes you need to add a load to simulate driving. If I had to guess I would say check the rear pinion bearing.

I did not try that, however the pinion bearing may be a good guess as the seal is currently leaking a good amount of fluid.