Hi
I have an 2007 XK8 Convertible here in Dubai and I requested Jaguar to check out a running sound from the rear of the car. I thought it was a wheel bearing. Their free-wheel test identified the differential as being the source of the sound and their notes stated, "Need to follow JTB00175v6. Estimate rear differential assembly".
The car has only done 98000km (61000m).
Does anyone know what this message means.
More importantly what does this noise indicate? Lack of oil or a more important problem??
I will try and ask Jaguar but it is not easy contacting the service team without going in.
Thanks

 

First of all welcome to the forum, when you get a moment stop by our new members area and say a few words

Now, your diff.

The TSB JTB00175 is a replacement program to upgrade the troublesome diffs in the 2006-2008 cars (a Ford/Visteon unit) with the new design from GKN that was fitted to later models.

You can see an example of the work done in this thread https://www.jaguarforums.com/forum/x...ential-114897/

Basically it's a replacement diff, driveshafts and propshaft. And it costs a bomb...

The noise you hear is most likely a bad bearing, caused by a defect in the assembly of the diff by the OEM supplier.

There are several options

- go with the complete upgrade from JTB00175
- rebuild your existing diff and hope that it's gonna hold
- fit the older style diff and driveshafts from the 4.0L S-Type

You can see some info here https://www.jaguarforums.com/forum/x...ebuild-151389/ and links to some other threads discussing this topic.

I would look for a secondhand diff and driveshafts from a wrecked 4.0L S-Type if I were you. It's the same ratio 3.31:1 as your XK.

 

Hi Cambo


Thanks so much for your prompt and very informative reply and advice.


I went back to the dealer and asked about the JTB and whilst he informed me it was a Jaguar Technical Bulletin advising a replacement diff (at around 30k Dirhams or 6k pounds) he did not say anything about troublesome diffs on 2006-2008 cars, surprisingly. He said that because my car is a US import to UAE the dealership would not be willing to "help me with the cost" even though the mileage is so low. I cant afford to change anything right now so will put up with it. I cant hear it with the top down or the CD playing! It's not a very loud whine - more the sound of an unbalanced wheel but without the vibration.


If the bearing or diff completely packs up what will happen? Does the back axel just sieve and I skid/grind to a halt? That's my only concern right now.


Thanks again
Regards
Piers

 

Interested too, in what happens if the diff does finally fail. I've got a howl that comes from the rear end as well (annoying, but I'm living with it).
When I had the diff fluid changed a few months ago, the indy shop said they saw some 'shiny stuff' in the old fluid, so its probably wearing away. I should take it back and have the fluid changed again, to see how fast it is wearing, but I haven't had time to do that.

 

What about a additiv?

I know this problem from my Corvette C6 (and a lot of other C6 owners) which had have noise from the diff.

They put a additiv into the oil and the noise was away.

Thomas

 

With a posi-traction differential you either need to use gear lube for a posi unit or put an additive in . I don't know enough about the e-diff yet but as far as the standard diff. all you need is the recommended fluid.

 

There is no E-Diff in a 4.2 it's an old school open diff, same as the S-Type, X350 XJ, early XF.

I doubt any additive will shut it up, if that were the case cars wouldn't be getting new diffs.

The cheapest/easiest way out of this is to get hold of a secondhand diff from a 2003-2005 V6 S-Type or XJ6 as they run the same 3.31:1 ratio as the X150 and it'll bolt straight in.

 

What about getting a Quaife limited slip diff? If you're going to pay for a diff replacement might as well get a limited slip one!

 

Hi Lads, in particular Cambo who was more than helpful. I found another thread in which Cambo gave me some of the part numbers. If you are interested this is the update of my story.

Since the second hand parts market is very poor and unreliable here in the UAE (Gulf) I decided not to attempt this route. I found a Jaguar/Land Rover Specialist in Dubai who is far more reasonable on labour costs than the JLR dealer. He found me an SType Diff but for about £1000 (compared to the JLR repaiur of new diff and axels for north of £6000, but he did not know how many miles it had done and could not give me more than 10 dyas guarantee it would not develop the same fault.

I decided to get new bearings and seals myself and my specialist said he would fit them for me.
I rang my local JLR dealer in UK (Guildford) from Dubai and bought the seals and isolators from them as attached. Keith there was really helpful when I rang and personnally delivered them to my UK home front door! Speaks volumes for the Jaguar fraternity I believe.
I then used the part numbers that Cambo gave me in another thread and bought them from Bearing King in UK.
I bought these for the half shafts: LM603049/LM603011 Timken @ £13.55 each https://www.bearing-king.co.uk/bearing/lm603049-lm603011-timken/3118
and this for the drive shaft:
M88048/M88010 Timken @ £12.51 each https://www.bearing-king.co.uk/products.php?search=88048
Cambo wasn't sure of the number but having searched Lincoln websites I managed to work out that this was Bearing Kings part numbers.

I had to go home for a long weekend in April so I brought the parts back in my luggage. About £40 for the 3 bearings and £115 for the Seals etc.

I took them to my speciailist and he got to work and then rang me to say there was a fourth bearing required and sent me the two attached pics.
This one is inside the diff on the pinion axis. They told me the part number they needed and said they could not locate it in the UAE so I found it on Ebay in the USA. This is the reference they gave me:
Timken Bearing Race Ford 8.0 inner NP 945727
12 days later it arrived in UAE (via UK!) and it was fitted. It's only the bearing race. They were expecting the bearing itself too but I had a look and the original didn't have a mark on it so I said that would have to do. From what I have read online, the Jaguar IRS is the major cause of their weak diffs so I figured the inner pinion bearing was least susceptible to wear and failure.
After nearly 4 weeks I now have the car back and sorted for less than £500 and it feels and sounds just fine.
So for others who experience what is apparently a common Jaguar problem I hope the info attached is useful.

All the best, and by the way - in answer to another posted thread 115mph on the way to the empty quarter in Abu Dhabi is my quickest to date since we have so many cameras in UAE - or I have the Mrs (My "Handbrake") riding pillion!

 

I thought the diff was going out I my son's 08. It ended up being a loose dust shield spinning and squealing on the shaft. A few dabs of sealant to refix it and the squeal went away.

 

I read this thread about a month ago with a really bad feeling the noise I had in my 07 XKR was the rear end. I just put Michelin Pilots on it and the noise is gone. No kidding, that's how much noise the Dunlops were making.

 

Ah yes, the ole can of "Noise Be Gone". The volume knob on the radio is a lower cost solution that also works as a temporary fix.

 

Uh oh.........

 

I don't know much about the Michelin's but when I replaced my rear Dunlops with Conti DWS the drone I had at around 60mph went away.

 

On top of this particular Jag diff (03-05 S-type) does the Lincoln diff from the same era bolt straight in as well ?

 

My 2007 Jaguar XKR has also been diagnosed with a worn differential. At 115,000 miles it has done twice as many as yours, but it is still disappointing that parts like this don't last longer on a prestige car and is yet more expense to keep this thing on the road.

I was really hoping it was a wheel bearing, unfortunately not! The garage that looks after my car is trying to track down a 2nd hand part with known mileage and if one is available, this should half the price of the replacement.

 

You look to be unlucky as there are lots of cars where that hasn't happened and it looks like hardly any posts where it has.

 

Yes, I seem to have been unlucky with a number of faults on my XKR. A few years ago the jurid coupling (rubber doughnut) split and the dealer told me it was very unusual.

It's not like I drive like an idiot, in fact the exact opposite and these parts have NEVER failed on any other car I have owned, so I can only put it down to poor quality components.

 

They must have saved them up to fit to your car.

 

Hi. I live in Dubai as well and just bought XK -2007, same symptoms unfortunately. Can you please share the garage you used to fit the parts?
thanks!