I just started noticing a noise coming from the rear end of my 97 xj6. It's not a whining or whirring, but more of a rumble when coming to quick stops, I can feel the vibration in the seat a little bit. I don't hear any noise while driving and stopping while going down hill, the rumble/vibration is more intense. Just turned 159,000.

I used to have a Dodge cargo van that had a bad diff that made a similar noise, but it was a constant rubbing sound, not just during braking....

I've put around 8,000 miles on it in the last 4 months and it's age is really starting to show...

 

My findings with mine in some sort of order:

1) Tailshaft centre bearing.
2) Half shafts NOT been greased since the factory. Lots of strange noises from those suckers.
3) Wheel bearings, NOT common. but that mileage may be a factor?.
4) Diff unit. Being as its a NON R, not common at all.
5) Tyres. Mine drove me NUTS (more than usual) when I got caught with "cheapo" tyres. Borrowed wheels and tyres from mates XJ8, SOLVED.

 

If you have access to lift, you can put the running car on the lift (in gear, wheels spinning) and use mechanic's stethoscope to pinpoint where the noise is coming from. Sadly, sometimes the noise goes away when the car is on the lift.

 

What's it take to grease the 'half shafts'? Do they have grease fittings?

.

 

Whats it take, let me see.

Grease, in a gun for ease of application.
300ML of JD, per fitting.
Car raised so your fat gut can get under it, or your trim taught gut if you are that way inclined, I'm NOT.
Out of P, and park brake OFF, so whatever safety measures YOU see fit for that activity. The rear wheels will need rotating by hand to get those fittings at the right angle.

Mine, and all the X308's I have been under have fittings on all 4 joints of the halfshaft. Some had a rubber dust cover, some did not.

These are the ONLY grease nipples on these cars that I know of. Some report grease fittings on the rear universal joint of the actual tailshaft, but I have not seen that so far.

 

It might also be worth looking at your brake pads. You might be starting to get "metal on metal" if they are badly worn. This can also occur even when you aren't braking, if the pistons are sticking a little and causing a fairly constant rub.

 

good call on looking at the brake pads, I didn't think of it because they were done around 15k ago... but, it does kind of sound like that...

Noticed today the noise only starts after things heat up.

I'm bringing it in to have the condenser exchanged as I wasn't able to loosen the bolts myself. I'll have him look at the things mentioned here as well.

 

Just my two cents worth, but X300's do suffer pinion seal leakage and very rarely get attended to. Consequently oil leaks out and the differential bearing on the opposite side of the crown wheel doesn't get enough lubrication and thus the rumble. Easy way to see, How much oil is on the "A" frame.

 

Jeez... turned out it was brake pads. Completely gone and the inside pad was rubbing.


I'm curious, my mechanic did the brake pads 25,000 miles ago and the invoice says he charged me for front and rear. He says that the front still look to have 60% life on them and the pads usually only last 17-18,000 miles. Does that sound right? Why would the rears wear so much faster than the front if he indeed did change both front and rears at the same time.


I have no reason to distrust him at the moment, but seems fishy....

 

Hmmm. A bit odd. Generally the fronts wear out sooner than the rears.

Dragging rear calipers, perhaps?

Cheers
DD