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Noise coming from my '89 xj6's rear

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Tophatchef

Jedi Hopeful
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While driving, their is this horrible noise of very strong vibrations coming from what sounds like the trunk area. I've padded the trunk with several layers of carpeting, and have even filled it, and the noise persists.

My father believes the noise to be the rear differential, and that it's oil needs to be replaced(or something along those lines).

If it is my differential, how would I go about fixing/locating the problem. If it isn't my differential, then what could it be, and how could I fix it?

Thanks
 
Check out the rear tyres, just in case. If the tread is seperating it can cause the vibration and noise, and it's not unheard of especially if the tyres are older. It could be the diff, of course. Has the noise always been there? Did it come on gradually or all at once?
 
Or, the u-joints in the half-shafts?
Or the main shaft?
 
The noise has been their at least the past 8 months (when I bought the car). I'll check the rear tyres tomorrow. The noise has always been their, but it feels as though it has gotten a bit worse, that or it's just annoying me more.

If my problem is the u-joints, how do I check?
 
Or a hub - they're aluminum with steel bearings & if not properly greased will wear badly.....I had to replace the passenger rear hub on my '85 because of that....if it is a hub, the tire won't turn as freely as the other side....mine started making noise in reverse only & finally almost locked up.
 
You can spend a lot of money trying to solve noise, when often you can eliminate certain areas early on.

This is where is gets scary.

For me, since I've done this for years, I would jack up the pumpkin, place 4X8 chunks (or 4X6) under the rear tyres and set it down.
This sets the position of the suspension as it would be in use.

Chock the front tyres, both sides, front and rear.

Engine off, keys in pocket, park brake off, in neutral.

I cannot recall the specifics off the top of my head on support on rear suspension, but, you might be able to support the car if you can get the jackstands out far enough to hold the suspension in a position normal for on-the-ground.
Mechanical advantage and leverage sometimes means that if you support the car inside of the center line of the whels, the suspension will try to unload, the control arms will [censored] to an angle, and the car will try to exit it's position upon said jackstands.

If you are unsure of you chocking skills, might be handy to have an assistant sit in the driver's seat to hit the brakes if needed.

Slide under back of car, grab half-shafts and check for rotational play, and up/down play.
I have been known to use a long, fat screwdriver or prybar to force rotation, looking for movement and LISTENING for noise.

Your joints have grease zerks?
Ever grease them?
Slip-shaft?

Then, check the companion flange at the sides of the pumpkin.
Been a lot of years, but if I recall, the u-joint assembly sandwiches the brake rotor to the diff companion flange, and slight prising on the disc to see if it wobbles will tell.

Check the main shaft u-joints next, same procedure, same greasing.

Then, jack it back up, check your wheel bearings and hubs for ply, noise, runout.

A good way to check for noise is actually by touch.
With car blocked on stands, slide under, touch the carrier, with you hand and fingers fully clear of any contact with rotating parts.
Have an assistant spin the wheel.

You have a bad bearing, you will feel it in your fingertips.

With radio, a/c, all that off, windows down, car on the ground, start it up.
Automatic?
Brakes on, shift to reverse while listening carefully.
Hear any "clink" noise?
Shift to drive while listening.
Hear any "clink" noise?

"Clink" is often the sign of loose u-joints.
When the slack runs out of the needles and cross shaft, the impact noise is transmitted to the hollow driveshafts, hence the "clink".

I have heard tyres make the noise, but generally heavy tread all-weather tyres.
Stacking noise suppressing material in the boot with no effect more indicates a mechanical issue, but, you never know.

If you don't hear the noise from the front, you can rotate tyres front to back and see if it changes.


Now, if you had a flatbed hoist (like a muffler shop uses), or an old-fashioned grease pit, you could just drive up on it and no jacking.
 
Couple of other things to check while you are under the car.
Rubber suspension mounts to body.
Exhaust system touching the body or chassis somewhere.
 
it's probably a U-joint in one of the 3 places where there are U-joints, they do wear out. I really doubt it is the differential but it doesn't hurt checking the oil level.

A Total lack of Lube maybe?

If you had the Factory Service Manual, you would know where to look and where to lube.

buy it here:

https://www.jaggraveyard.com

https://www.lbcarco.com

or any Jaguar Dealer.

Ex
 
Okay, I finally had some time, and daylight to check the tyres... they are fine and relatively new.

What I did not do was check the differential oil level. I could not decipher how to. If anyone has some detailed instructions on how to do so, please tell me soon, otherwise I will have it checked at a local Eco Lube.

I also did not check the bearings because I was instructed by a neighbor to inquire on the amount of give the hub and axle should have. The passengers side moves more than the drivers side.

Thanks
 
Axially? The outer joints take the brunt of the stress. They need regular lubrication. That'd be the first place I'd suspect.
 
Well, today I checked my bearings, and noticed that they are not in great shape, and they show some signs of having been heated. I went to the auto parts store, and picked up a new pair. I just have one slightly major problem. When removing the assembly, everything sort of fell out on me. I only have a Haynes manual, and it tells nothing about rear bearings, let alone putting them back on. I need some major help! I still have all the pieces, and a vague idea where they go. If anyone could do their best to instruct me on how to put everything back together, I'd be very great full(please try to simplify it as much as possible for me, I'm doing by best to become Jaguar savvy).

Thanks
 
This is a joke, right?
Been a lotta years since I did rear carrier bearings on a Jag, but if I recall, falling out in pieces is not part of the process.
How did you get the hubs off?
How did you get the stub axles out?

I mean, for all I know, I'm thinking of something else, but boy, falling apart is not in my memory bank.
 
I got the hub off by removing the breaks, and undoing the nut in the center. After that, it pretty much fell/leaned forward, and I had one piece fall out of the front (not the bearing nor seal, some other piece), and on the inside, a seal(I think), and the other bearing practically fell out along with a tiny ring.

As for the stub axle? I don't really know what a stub axle is (sorry). I'm working on becoming car savvy.
 
How did you get the nut loose?
Aren't those something like 150ft/lbs of tork?
Stub axle is the....stubby axle that has a U-Joint fitting on one side, goes through the bearings, and the securing nut on the other end.

I just don't recall them coming apart that easy.
It's been 20 years or so since I did them, so who knows.
 
Well, for starters, THANK YOU for the breakdown!

I got the nut loose with a big breaker bar, and using the force of my foot to take that off, so that made it way easier.

My new trouble, is getting the spindles (I believe that it's part of the stub axle) to line up and fit properly to attach the nut in the center. Is their any trick to doing this? I've been certain to lift the other side of the car so everything will spin to allow ease to line up, but I just can't get the stub axle to pull all the way through to attach the nut.

When do I re-attach the allen wrench bolts? Before I reassemble the bearings in the hub?
 
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