Howdy folks,
been a while since my last post. Still plugging along with my 99 XJR with about 98k miles.

After using the car in our harsh winter, when the weather got a bit warmer, I hosed off the underside with a regular hose/nozzle, not a pressure washer or anything. Since then, the car has made an awful grinding noise from the rear at anything above walking speed. The grinding does not go away at higher speeds and applying side to side load doesn't change the noise. Accel or decel doesn't change the noise and its road speed dependent, not engine speed. Its quite loud and initially appeared to be something like a rock stuck in a brake pad, a rubbing dust shield, or potentially a bent heatshield rubbing the driveshaft. I have checked all of that and found nothing wrong. The driveshaft guibos are new and the center bearing seems totally fine.

Thinking maybe I washed the grease out of a ujoint, i regreased all the joints on the rear propshafts. Despite this, the grinding remains. It doesn't feel to me like a bad ujoint as there is no clunking or noticeable play. I suppose it could be a wheel bearing, but it does not seem to have any of the typical symptoms. The noise feels wrong, it would have failed out of nowhere, there is no play in the wheel, and high speed turns don't change the noise at all.

Before I start throwing parts at it, I'm hoping somebody has an idea of what else it could be.

Also, diff oil was recently changed and there are no apparent leaks.

I'm at a bit of a loss here so any idea would be helpful.

Thanks.

 

There are a few TSBs on noises to cover the bases

There is the thing on Diff output bearings getting dry from a plugged fill port vent screen , and can be repaired yourself with Diff stayon car

see bottom of list

JagRepair.com - Jaguar Repair Information Resource

 

The X308 and X100 use the 14HU with a different output shaft/stub axle arrangement with inline pinion/crownwheel but the idea is still the same.

 

I guess it can't be as easy as a stuck/corroded hand-brake-cable having the effect of pushing the pads on one or both sides a bit onto the rotors (discs) while driving?

 

The handbrake cable has NOTHING to do with the brake pads.
The handbrake uses SHOES inside the rear rotors like a drum brake setup.

 

If comes to this area

j 1998 - 2003 (from 812317 To F59525) (x308) Classic / Differential Assembly | Jaguar Land Rover Classic Parts

item X . Y . Z

Bearing kit offerings on E - bay but...................................

 

OK. Then maybe the brake shoes being stuck due to hand-brake cable being stuck? Just an idea. Doesn't hurt to check out the cable, I guess. And checking, if releasing the handbrake actually releases the levers on the brakes, or if the levers are stuck and all you get after releasing the handbrake is slack in the cables...

 

thanks for the responses. handbrake shoes are not stuck or contacting the rotors. In fact, with the rear wheels off the ground, spinning the wheels doesn't result in any obvious noise. will have to explore those diff bearings in more detail

 

Keep the mind open and note your observations as I observed myself the diff output bearings on another X300 and can see how not easy to discern

There are also some TSBs listed under the same earlier X300 chassis that made tge list and missed the X308

See TSB on removing the output bearing retainer / collar if your issue comes to it

JagRepair.com - Jaguar Repair Information Resource

TSB coming

 

A guess: the rubber bushings to the exhaust hangers are dried out and vibrating. Had the same problem, louder at higher speeds (maybe more due to road surface variations than what you describe): silicon spray brought silence and contentment, in my case.

You are sure you got enough grease in those two zerk fittings?

 

Hi Jim, just to be safe, I added grease to the shafts, which didn't change much. I spent some real time under it today and while the drivers rear wheel makes a bit more noise than the other side, its an intermittent noise that feels more like a bit of brake pad deposits than a wheel bearing or bad Ujoint.

When having the car in drive on jackstands, you hear the noise pretty plainly from the little tray right behind the center console, which lines up exactly with the center propshaft bearing. While I'm surprised this would have so badly failed this quickly, I don't have any other logical solutions. Literally everything else looks great, there is no play in any wheels, plenty of clearance around the wheels and the driveshaft, etc.

Worst case I waste $200 to replace the center shaft bearing, but the noise leads me no where else as this is the only thing that is bolted up to the body.

 

to close the loop, i pulled the driveshaft today and the center bearing was in fact toast. very gritty. Pressed off the bracket and rubber surround and used a drift and a hammer to knock off the old bearing. Will press on the new bearing and hopefully solved the problem.

 

done...nicely quiet now.