Ok so this morning discovered that going the S-Type 4.0 route is a non starter.

This route was previously suggested elsewhere in this forum.

The half shafts from the S-Type are totally incompatible and I do not want to get involved in some expensive welding exercise.

Pretty annoyed at what I have been through so far however unless someone can definitively tell me that the Ford 28 spline LSD does not fit in my XJR diff I am going ahead to try and fit it.

On very rough test fitting it looks as if it will fit. Also the axle shaft race and bearings taken from the XJR diff are the same as for the Ford LSD.

 

If you go back to this thread https://www.jaguarforums.com/forum/s...install-86430/

A group of us bought a spare Gen2 8" diff and sent it to a specialist diff shop (DTS), for them to "fit an LSD" and the end result was that the standard Ford 8.8" center does not fit inside the Gen2 8" housing, even after grinding some metal away.

So i'm afraid you're going down the same road we tried, been there done that.

In that thread, post #373 and #379, you see comments from forum member kiloken in the UK,.

The halfshafts in an X350 and an S-Type are the same part numbers (for equivalent engine type)

So i'd like to understand where the "totally incompatible" part is.

 

https://www.jaguarforums.com/forum/j...-134733/page3/

The above thread, posts in the 40+ range, is what I was going by.

The first pic shows the outer CV joints from a 2004 XJR and a 2000-2001 4.0 S-Type. They are significantly different in length and width and that includes the diameter of the splined shaft.

The separated reluctor ring from the S-Type is of a wider diameter than that of the XJR and with a different number of teeth/notches.

The second pic shows a 2004 XJR half shaft alongside a 2000-2001 4.0 S-Type half shaft.

The right and left S-Type half shafts are considerably different in length.

The XJR half shafts are not and on Ebay they are listed as interchangeable between left and right.

 

The 4.0L diff housing is wider than the 4.2L diff housing, and if you look at the centerline of the diff (from the pinion) you can see why the 4.0L shafts are shorter than the 4.2L ones, and also different lengths.

See this picture;



The 4.0L diff on the right is wider than the 4.2L one on the left.

The half shafts may be listed as interchangeable left to right on eBay, but they sure as hell are not in the JEPC.

If you see here;



The diff is not symmetrical from the centerline (pinion) so the driveshafts are different lengths left to right.

 

Does the outer CV joint from the XJR fit onto the 4.0L S-Type half shaft?

 

No they do not unfortunately. I was hoping that they would but the splined shaft on the S-Type is of a slightly wider diameter than the XJR counter part.

I do not believe that the S-Type outer CV joint will fit my 2005 XJR hub plus the reluctor ring has a different notch count.

I have both differentials on my workbench so can see the differences.

 

Makes me wonder if "kiloken" in the UK used 3.0L driveshafts not 4.0L ones...

Could be that pre-2002 3.0L S-Type shaft is a smaller diameter and the XJR CV will fit them?

 

I need to find out without spending too much!

 

Will a Quaife unit that fits an XKR/XK8 1996 to 2006 fit a 2005 XJR ?

Reason I ask is that some units now seem available in the U.K.

Quaife sold their remaining stock, of these units, a while ago to someone in the UK and they may have just turned up.

 

Correct me if I'm wrong, you try going the S-Type because it would be much cheaper than the Quaife one?
And would those reappearing Quaife units (do you have a source?) be more affordable?

 

That was my original intent however it looks like it is costing me more than I originally thought and I am at the point where I do not want to throw more money on a project that is not going to work.

I will try and sell what I have purchased so far on Ebay to cut the "cheap alternative" losses. These parts will be difficult to sell I know.

A Quaife QDF3W unit will fit I have just confirmed.

It will cost more but will involve FAR less work and I know it works.

 

No, totally different unit.

The correct Quaife centre for the X350 is the QDF3W

 

Its amazing that Jaguar would build an XJR and not fit it with a posi differential...

 

My source is: Motorsport-Tools in the UK.

Got to them thru Ebay where they list the QDF3W at a price that includes VAT.

Contacted them directly to get a price including shipping less VAT.

 

Shame it didn't work Jackra. I've got the 4.0 s type diff and shafts sitting at home, but I'm reluctant to buy the 8.8" Lsd after reading this now! Maybe I should quit while I'm only £90 quid in...

 

Yes I am disappointed to say the least. Plus I picked up a new out of the box Ford 8.8" 28 spline LSD at a huge discount from someone who
gave up on a project. Now I am selling it for the same reason!

Originally I wanted to go the Quaife route but everyone listing the QDF3W when contacted did not have it in stock and went to Quaife to get it and could not.

Then when I phoned Quaife direct the person I spoke to said they had sold all remaining units to someone. They gave me that person's phone number which when called had a full message box.

I really want an LSD in this car!

Now these units seem to have turned up and I have ordered one from the UK. losing the VAT saves quite a bit.

I have an XJR diff stripped down ready and waiting and new bearings on order. I did not touch the pinion gear so hopefully do not have to adjust its position when installing the Quaife.

We will see how this turns out.

 

These guys sell the QDF3W37 for XKR's after 2006.
Is it the same than QDF3W (Cambo was saying that the XKR unit from 1996 to 2006, maybe a different reference, does not fit XJR)?

 

They are selling both and its the one for the XKR 2006 on that I am getting and I am not 100% certain of the fitment since there are a couple of letters after QDF3W but we will see.

It will be at least a couple of weeks before I get delivery of this unit.

 

Good luck with the quaife jackra, our cars could really benefit from an LSD even stock so I'm sure it'll be a worthwhile mod with the power upgrades you've done. I will have a think on whether to have a punt or not as I'm in the same situation you were in, someone with a failed LSD project for their STR is offering to sell me it!

 

what I found with the Ford LSD was that even tho it has the same length as the Jag gear set I could not insert it back into the Jag XJR 4.2 diff housing when the ring gear was attached.

My next step was going to be to try fitting with the ring gear unattached but roughly in position to see whether both would fit and then attach the ring gear to the LSD when both were inside the diff housing.

I still feel that this is a possibility because I only needed about an extra 1/4" of "play" but am past that point now.

When I placed the Ford unit, without the ring gear, into the XJR diff housing there is plenty of clearance around it.

The axle bearings and the ring gear when placed on the Ford unit would be in exactly the same position as on the Jag unit.

Just went out and tried it and it just does not give the clearance required.