Rear growling noise

[juggernaut2874]

My 02 EB 2WD with auto tranny has developed a rear end growling noise that is noticeable when the RPMs go above 1200. The noise is only present when I'm on the accelerator and it does not happen when I let off the gas. It does not happen/increase when I turn left/right either. I haven't been able to pinpoint if it is coming from a particular wheel or from the differential. There is no play in the rear wheels like when you're checking for older style rear wheel bearing issues. I'm about to make a trip from MS to CA and am worried about the noise. The rear end fluid is good and at proper level.
Does this sound like a rear wheel bearing, differential, or transmission problem?

 

[juggernaut2874]

Upon further inspection last night, I was able to locate the rumble coming from the rear differential and not from the wheel bearings. I believe the pinion bearing and crush seal are bad. When I pushed up on the driveshaft/U-joints at the differential connection there was some definite movement/play. This should be firm with no movement, correct? I'm guessing that when the RPMs go above 1500 the play in the pinion bearing causes excessive vibration/wobble thus causing the rear end growling. I will replace these parts, drain and fill the diff with synthetic and friction modifier and see what happens. I will let you know.

 

[manaen]

the vibration is coming from the gears not meshing properly due to the worn bearing. There should be no play in the pinion. You probably want to shop for a low mileage rear from a salvage yard. If it have been running long like that your gears will be toast. You may be able to replace the bearings however the old gears will not mesh properly anymore which will cause them to heat up and wear out quickly.

 

[rrgone]

juggernaut

Holy sh#&, where did you get that EB? Was it flooded during Katrina or something? Talk about one thing after another....

 

[juggernaut2874]

It made it through Katrina unscathed except for a pine tree falling on it and cracking the windshield while we were evacuating. Bought it in TX from a dealer used with 60K miles on it already. Fixing one little thing after another plus I'm making extra sure it is ready to move to CA. Thanks to all od ya'lls help the problems haven't been too costly and I know 10X more about Explorers now. First year of the 3rd Gen Exs and stuff is what I contribute most of the problems to.