Hello Everyone, I'm a big fan of this site. You guys definitely live and breathe Jaguar. I have a 1984 XJ6 Series 3. 89k on the odometer. Let the car sit for four years. Did everything to get it straightened out and she purrs. The problem is there is a chatter or vibration coming from the rear of the car with a loss of power. It almost sounds like squeaky hinge on an old house door or a hydroelectric type noise if that makes sense. I greased the rear in all designated places. The u joints oozed out black thin worn out greased. Looks like it was never done ever. Pushed enough through till it subsided with newer coming out. Drove and repeated. The rear differential was black with some chips like sand. Put in Valvoline 75/140 for the florida heat.The noise doesn't start right away. It takes a few minutes. I'm going to drop the whole subframe and replace everything. It's not a universal. Wheel bearings will be replaced as they do make noise at higher speeds. Is this chatter or pump like sound the rear differential? I'm completely lost. Lash maybe. Any help is truly appreciated. I do have the factory manual

 

Welcome to the Forums.

The actual rear end is a solid thing in real talk.

Knocking between R and P is Dogbone shims screaming for attention, and more common than admitted, NOT your noise, yet.

Tailshaft centre bearing, they do cause issues, more of a thumping than a rattle.

Park Brake caliper, pads, etc are a contentious issue, and cause all sorts of odd noises. Some claim, good on them, to get all those bits out, and back in PROPERLY, with the cradle in the car. I take the cradle out, 2 hours, and then do it all (without being silly), and repeat in 30 years time.

The actual Brake Pads can be noisy, but 99% only when applying the brakes.

Shocker bushes, age related, and can rattle badly.

One I had that really stumped me (XJS), eventually found the actual cradle cracked around the 4 top diff securing boults. Weled, ground out, Loctied, mpved on.

Loss of power, oops, no idea yet.

 

Grant, please tell me about these "dogbone" shims.

 

Chips in the diff oil? That doesn't sound good. You may have a diff overhaul in your future.


How did you determine this?

Did you disconnect the shafts and move the U-joints with your hand? If not, you can't rule out U-joints. The action when moving them should be butter smooth. I've replaced many U-joints that looked OK but were seized-up, or partially seized.

Cheers
DD

 

I think Grant is talking about item #6 in this illustration:

https://parts.jaguarlandroverclassic.../brand/jaguar/

Cheers
DD

 

I'm not ruling anything out.Im going to drop the cage and replace everything. It's not expensive and I have piece of mind. This will include all driveshaft universals and what I call the hangar bearing. Rear wheel bearings. Trailing arm bushings etc. While it's out I'll replace calipers and possibly disks since it's apart. The power loss I'm hoping isn't a binding issue. I've replaced the fuel pump and it didn't make a difference. I'm wondering if possibly air or some sort of vapor lock is causing the pump to squel. Or,Maybe it's getting an intermittent power loss at the pump. There were filings in the rear as I've stated. It's an intermittent problem. Only after it warms up. It's usually when the car goes into second gear. I'm thinking because of the pressure of the taller gear maybe. I'm dumbfounded. I'll check the tailshaft while the cage is out and replace the seal. Check for playing. The differential is scaring me. My dad had a new 82 XJ6 and the rear went out at 2000 miles. Thank You for your replies everyone. I'll keep you updated. I drive it daily. Maybe 25 miles daily. The rear does have play. Forward to reverse and at slow speeds on my road when i take my foot off the gas at around 10mph.

 

Here ya go.
Fill the beer fridge first, you must keep your fluids up, ha.

 

Heineken is always on hand. Maybe a few other things. Thanks for the tip. Like I said. I'll change everything because I wanted to do that anyway. I love how the cage drops for repairs. I absolutely love the car. It's a rolling piece of art as far as I'm concerned. Rarely a day goes by where I don't get a compliment on her. People don't realize the work that went into the body. It's not some machine stamped out fender. It's hand formed from my understanding. I respect the car and think it deserves to be basically brought back to new. Front end needs ball joints and rack. I'll replace everything including all rubber. A frames. Motor mounts etc. I understand how people are infatuated with the XJ6. It's just beautiful and there's nothing like it. It has the American horn. I'm thinking of putting the high pitched English horn just for kicks. The ac recently took a dump. Original R12. Upgrade coming as I have replacement parts. Air pump is going out as well. Including Cats. Florida has no inspection or emission controls as other states.

 

For the UJs in the rear axle, I suggest you use the type linked below (from Rockauto in my case), which are far far better quality that the others available. I suggest that you use the sealed for life for the outers and the greasables for the inners, as the outers are hard to grease with this style of grease nipples.
This is a thread you may find useful:
https://www.jaguarforums.com/forum/x...ebuild-225834/
and this
https://www.jaguarforums.com/forum/x...ebuild-289288/


My very strong recommendation to anyone doing the rear axle driveshafts is to use these items.
https://www.rockauto.com/en/moreinfo...78647&jsn=1624

Sealed for life
https://www.rockauto.com/en/moreinfo...t=2392&jsn=616
and greaseable
https://www.rockauto.com/en/moreinfo...t=2392&jsn=614

 

Grant,
Thank you for your write up.
I've known about the dog bone shims, but not seen the set up procedure so well presented.
I've experienced the clunks when the shims have fallen out, and I've seen cars that had the U shaped shims fitted from below, rather than above. If fitted from below they can fall out.
Regarding using alternate shims, cutting the corners out of camber shims may work although not as easy to insert. I think they come in various thicknesses, but I see 20 thou listed here
https://www.martinrobey.com/jaguar/e...uspension/1760
Thanks again,
Rob

 

Thank You in advance. Now I know exactly what I'm looking for. This is why you fine people here are amazing.

 

Thanks Robert.

I got a Pack of Steel shim stock, maore than likely Stainless, 15 pieces, about 6" square. Joys of working in the Auto Parts Industry forever, lots of "special" things if you look.

Cutting what I wanted was simple enough, The fact they cannot fall out made that cutting very satisfying.

That was back before Internet and Forums, so Good Old Common Sense was the flavour of the day.

 

You want to start disconnecting things and have a good look around. Based on the chatter and loss of power... I'd have a looking at the Center bearing on the drive shaft as welll as the u-joints.

 

The center bearing came to mind. I call it a hangar bearing from my Semi Truck days. There's some things I know need to be changed. The center bearing is on my list. The car has almost 90k on it. If I'm changing all the U Joints I might as well change everything while it's apart. It's really not that expensive in the grand scheme of things. I prefer to have all new. This way I know exactly what's going on. I'm probably not getting rid of the car ever. It's a rolling work of Art. I absolutely adore it
I can easily see why people have a connection with Jaguars. Especially the older models

 

Well,Finally got a chance to check out the Rear hub. Jacked up and shook the wheel. There's play. I'll tear it down and clean everything out to see what I'm dealing with. I'm betting the race is probably shot. If it isn't pitted or grooved it might be ok. I'll probably just replace the bearings and races. There's a kit on British parts that has the OEM Lucas Jaguar bearings, races and seals. 58$ with the shipping. There are other kits about 78$. I might just go with the Lucas. They are probably Timken or some other quality manufacturer anyway.