Ok. My 99 XJ has ALWAYS had what sounds like bad hub bearings when driving over 20MPH. I replaced them when I got the XJ a few years ago and I *just* replaced them with Timkins again when I replaced all my front-end hardware too.

Still sounds like a bad wheel bearing. It's quieter in the morning/cold but gets louder when it warms up.. Long interstate driving is obnoxious. Still feels like a bad bearing. Not high-speed whine. Sounds like severe tire noise but cannot hear when I hang out the window. Transmits thru the steering wheel as I slow down.

I put the Jeep on a buddys lift today at noon and the pinion input is rock solid and not leaking. I pulled the front DS last week to check the joints/sleeve so its not even in the picture.

I *just* redid my axle seals on the D30 last month and I had the carrier out and I didn't really check the bearings. My bad...

The XJ has 255K miles now and I'm pretty sure the previous owner ran the pumpkin dry as someone had already replaced the oil seals in there.

Any input here?

Bonus pic of parts..

 

Id see if the noise changes in 4wd verses 2wd. In 2wd that front pinion and ring is not loaded much, just free spinning with tires, in 4wd it is loaded, thus Id expect it to make different noises if pinion is at fault here.

You can wiggle the pinion input to feel if it is loose or not.

Drive shaft inbalance might also make noise, any dents, or signs of a damage to drive shaft, how is the U Joint.

An out of balance wheel, or bulged tire can make noise, and shimmy the steering (swap front to rear tires to diagnose this.)

Dragging brake with a warped rotor? Do the brakes pulsate on application, if so, this might be it.

Pull the cover, degrease the gears, and run a pattern check, if bearings are shot, the pattern may be telling,

 

I have removed the front driveshaft. The noise is always the same once it warms up with or WITHOUT the front D/S... I already swapped tires. Rotors, calipers, pads and lines were replaced. Brakes don't pulsate when applied.

It's for sure a bad bearing..

Bonus pic of the rotors on the XJ when I bought it. The rotors were just getting into the "wear bars" so I figured I should replace them anyways.

 

I wish you could have snapped some good pics of the ring and pinion gears. I have been in a number of diffs, and a porous ring and pinion will be more noisy than bearings. If that is the case, you can try adding Power Punch differential additive. It has moly in it and will fill in some of the pits if they are not too bad and quiet it down. If the PO did run it dry, the gears would be bad before the bearings

 

Usually, if you take your vehicle to a very experienced diff/gear shop, they will take it for a test drive free, maybe on a hoist and give you a diagnosis that is pretty accurate

 

When I changed the front axle seals on my sons 98 xj I found the carrier bearings were rough and noisy.

My local diff shop replaced the bearings for me. He said the factory bearings were known to go bad if the diff runs low.

He said the factory bearings are not the best quality.

 

Ok. I will see if I get time this weekend to tear it down again. I will snap pics too. This sound is driving me nuts. Driving the Camry today. ugh.

 

All we have around here is large chain shops and small janky outfits that I wouldn't trust to change my spark plugs. I tried calling around a while back for a shop to regear my 92 XJ. I was NOT paying $3500 PER axle with my parts for them to mess with it. Axle shops here are a joke.