Hi all,

So I've been given the grim news that there's bearing play on the right side of my differential (where the diff connects to the axle shaft). My mechanic said that the only solution is to fit the redesigned diff (of which he is currently trying to source a good used one....i know....good luck lol). This has me wondering....is there any reason why the dodgy diffs can't be rebuilt with new bearings/seals as long as the internal gears are still in good working order? Has anyone ever successfully done this or heard of this possibility? Thanks.

 

I do not see why not. It seems like a number of members on the forum have had new seals fitted. I think the bigger issue is how long the new seals will last. I recall one forum member reporting that they are on their third set. It seems this contamination caused some seals to fail, and I do not recall hearing of any planetary gear damage.

This is a really troubling issue for me as I firmly believe Jaguar should be held responsible for this CF. They knew there was contamination, they engineer a fix for the issue, but it was only a TSB. IMHO it should have been a recall. Jaguar is not standing behind a known defect and the fix is very expensive and now the first XF's are in the $15k range, the cost of this repair is approach 50% of the total cost of the car, which makes for a really hard justification.

 

Thanks for the reply. Replacing the seals only would not really be rebuilding the diff though (I've been through multiple seals failures on the right side where the diff meets the axle shaft only to be told now that I have bearing play - I bet I had bearing play awhile ago that wasn't caught, hence the constant seal failure). Those seals keep getting destroyed due to the excess play in the bearing. The only permanent fix would be to rebuild the diff by replacing that bearing, otherwise new seals will continue to fail. As the car moves the excess play creates friction on the seal and, as well, allows gear oil to leak out. It was the contamination from the factory that is ultimately causing premature wear on the bearings, which is, in turn, putting undue stress on the seals. People are replacing seals because its the only part that seems somewhat serviceable. Replacing the bearing would be attacking the problem at the source IMO.

I was told that the differential is non-serviceable but I don't see why that would be. A replacement is the easiest option from the dealers/mechanics point of view but there's no way in hell I'm paying $10k for a new diff setup. I've reached out to Jag corporate about the diff issue but don't expect much from them.

 

I pulled up a couple of old threads. It looks like you know about the Quaife option and you have posted in nearly ever diff thread so you probably aren't going to get much new info on here. Do you know the exact component that is bad on your diff? I'm sure a machine shop could fix just about anything. A mechanic would typically source parts for replacement. They wouldn't machine a new part. The diff should be removed and brought to a good machine shop or possibly a shop that specializes in rear ends and has the ability to machine parts. I'd think a good bet would be that a rock crawler type of shop would build custom diff parts and could fix this issue without much work.

 

Thanks for the reply. I've reached out to a shop that rebuilds diffs and inquired to see if they can help. They are trying to source replacement parts. It looks like it's just the right side bearing (where the diff meets the axle shaft) that is the issue. The play in that bearing is destroying seals in short order. All other bearings and seals seem to be good with no play. The custom machine shop is a very good recommendation. I'll look into that if the diff shop can't source any replacement parts.

Other than that I've considered installing a used diff with good bearings. The ones used in late model x types and the early XFs (like I have) seem to be reasonably priced. the quaife option sounds good but honestly given that the gear set in my diff appears to be good I don't think I need to look at that option just yet.

 

Do you mean late model S-types? I wouldn't have thought the AWD V6 X-type diff would have been the same.

So the issue is just worn bearings and that there are no replacements?

 

Yes sorry S types. My mistake. The diff is part #C2C34880. I was looking online at a few used ones and it specifies that it's compatible with:

S-Type 2.5 V6 Automatic 2002-2007 (VIN Range M45255 through to M99999, N00001 through to N99999)
S-Type 3.0 V6 Automatic 2002-2007 (VIN Range M45255 through to M99999, N00001 through to N99999)
XJ6 3.0 2003-2010 (VIN Range G00001 through to G49700, H00001 through to H31470)
XF 3.0 2008-2011 (VIN Range R00001 through to R41865) not Diesel
XF 4.2 2008-2011 (VIN Range R00001 through to R41865)

It seems like the bearing play on the right side is the only issue. No other play or leaks from anywhere else. My mechanic said that there are no replacement parts but like I said I've reached out to a shop inquiring about a rebuild. I've also just reached out to a couple custom fabrication shops to see what they can do for me. Ideally I'd like to get all bearings and seals refreshed to make sure the fix is good for quite some time.

 

Driveline shop just got back to me. They can have timken make custom bearings but I'd be without the car for 2 months and $1500-2k lighter. Hopefully one of the custom fabrication shops that I've reached out to have a bit better news.

 

Does anyone have access to TSB JTB-00175? It basically lists all the parts required to do the diff upgrade. I can't find a PDF copy for the life of me. Thanks.

 

S-Type posts are better in the S-Type forum but at least I saw this one!

The file's too big, though, so the forum/site prevented its upload.

 

No worries. Thanks.

I was able to get the list of parts required from my dealer. $11k to do the swap. Didn't know whether to laugh or cry when I saw it.