As mentioned in the neutral thread, I'm chasing a noise in the differential. Car is a 94 V12, has 98,000 miles on it.

It's a whump whump, whump sort of noise in the diff area. I used my stethoscope all over the diff and the output shafts and I can't pinpoint it. Of course, it's impossible to get to the rear diff cover to listen to see if it's carrier bearings, but it was loudest at the left output shaft. Pinion bearing seems quiet. Just moving my head around, it seems louder at the left side.

Here are 2 videos. One is at 40 km/h, the other at 20. Both are looking at the left side flange.

20: 40:
What are your thoughts? Output shaft bearing noise? Tooth backlash in the crown and pinion? Carrier bearings? I think those are about the only 3 possibilities.

My next step is to pull the output shafts and run it again and see what happens.

 

If memory serves me correctly you can replace the output shaft bearings without dismantling the diff. This would be easiest place to start.

Excessive backlash usually causes clunks and then diff whine when the teeth wear.

 

Sounds like output shaft bearing noise to me


Cheers
DD

 

Tonight I pulled the left side output shaft, and ran the car. Noise is still there, so I'll pull the right side tomorrow.

The gear oil looks nasty, I have a feeling it's factory fill. Its left a sludgy deposit over everything.

 

Both output shafts are out now, and the noise is still there when I start the car, so it is internal to the differential. Now to drop the IRS and pull out the diff. Unfortunately, I supported the car on the radius arm mounts when I jacked it up with my bridge jack, so I have to reposition the jack. Not a lot of space there to support the car. I certainly never anticipated having to dive this deep into the rear end.

 

You can not drop the diff with the rear end in the car. It's pretty easy to drop the rear, hardest part (for me) was the radius arm bushes. I had to cut (drill infact) the rubber out. So a new set might be a good idea.

Just getting the diff out of the cage requires a complete dismantle. So while you're there may as well make sure everything is in good condition.

Check the inner and outer fulcrum shaft bearings. These tend to wear unevenly as the only go through a small radius.

 

I've done a complete rear suspension rebuild before, on my 1966 S Type. I've had good luck getting the radius arms off with a block of wood, a prybar and an air chisel to give some vibration. The vibration of the chisel combined with pushing down with a prybar usually got them off in no time.

I just hadn't planned on doing an IRS rebuild to the XJS!

 

I have stripped down the differential and discovered the source of the noise! Unfortunately. The pinion cross shafts which carry the bevel gears inside the limited slip unit have broken. Every gear inside the limited slip unit has impact damage and/or pieces missing.



The carrier bearings are also in bad condition, with a lot of slop. As you can see, the rollers are badly spalled and missing pieces.





Given the state of the damage, I'm going to start looking for another differential or IRS, as some of the damaged gears are now NLA. Probably easier to put in another diff than repair this one. It's probably not even useful as a core.

 

Ouch! That is one bummer... I hope you get a new diff ASAP! Luckily there are plenty out there

 

That really sucks. Maybe a good opportunity to go to 3.55 gears. Good luck

 

I've seen some messy internals of differentials in my days. I have
never seen one that bad...


Sure is a lesson to all as to the importance of lubrication.


Core value, I doubt it. If the iron monger offers to take it for free, do it.


Carl

 

I already have 3.54! That's what the cars with the 6.0 have, along with the 4 speed transmission.

 

A friend of a friend is a Jag/Aston diff rebuilder in England. Says he sees things this bad maybe once a year... Apparently the things that are broken don't usually break, even in racing use. He figures the car was very much hooliganed before I got it.

 

Like cutting donuts ? That is what my generation called it. the local
"hooligans" call it "side showing".


Good luck on the "new' one.


Carl

 

Nowadays they are 'Hoonigans' copying Ken Block's Hoonigan slogan...

 

Things are looking up, it appears that Dodge/Chrysler 8 3/4" diff used the same limited slip up until 1969. The axle splines are different, but the internals otherwise appear the same. Also used in Ford truck 4x4 front axles in the 70's and some Jeeps. I am heading to the junkyard to investigate!

 

Yep, the Dana 44 hemisphere will fit the Jaguar diff housing and if memory serves me correctly you can get the Dana with 19 and 30 spline output. The crown wheel bolts are 3/8 not 7/16

Yep here goes

http://www.ebay.com.au/itm/Auburn-Ge...MAAOSwPe1T4-wj

 

There are loads of guys who use the Jag IRS in kits etc. These guys have done most of the work to fit Dana 44 into the Jag housing


Jaguar Differential Build

 

Yes, I have seen Daze before. He asked a lot of questions on Jag-lovers when he was doing that project. My ring and pinion is good, so I can reuse that. It's the internal parts of the Powr Lok that I need, of course the parts that broke are NLA from Jaguar now.

The biggest problem (although solvable) with using a Dana 44 ring and pinion is the splines of the pinion shaft don't match the Jaguar flange. The usual solution is a U joint in place of the flange, but that makes it more difficult to remove the IRS in the future.

 

Lots of Jeeps used 19 splines. Apparently the Powr Lok is the strongest of all the limited slip devices, and the Jaguar version has the strongest case of the various Power Lok units. Both Ford and Chrysler/Dodge have used Powr Lok in the past.