I want to intall a LSD in my 05 XJR. Cambo stated he wanted a older 4.0 S-type. From what I can tell there is no difference between a V8 or V6 car as far as the rear diff. is concerned. All have a 3.31 ratio from what I can find on ebay at least for the US market. I can get a better deal on one from a Lincoln LS since it doesnt have the Jaguar name attached to it.

I am also working on a Jeep TJ rear axle up grade as well. I am trying to source a 8.8 axle from a ford explorer. Some have LSD in them but there are two axle splines offered , 31 and 28. Of course I want the 31 for the jeep.

I know I will need the axles from the S-Type or Lincoln LS.

Can someone tell me what the axle splines are?

Plans are to use the LSD from the Explorer rear end in the S-Type or Lincoln. The next obstacle will be the programming with the help of the Moscow Leaper if I use the 3:31 ratio.

Thank you, Woodford Jag

 

The Jag diffs are 28-spline.

Using the 4.0L V8 S-Type diff and half-shafts in an X350 is based on a a lot cross-referencing, summarised as;

The S-Type R and the XJR have the same diff and driveshafts (p/n's in JEPC)

The 4.0L V8 diff and driveshafts have been installed in an S-Type R. source is Kiloken who did this on his car.

The p/n's for the 4.0L V8 and the early V6 S-Type driveshafts are different (up to VIN M45254), while the length would be the same, there must be a reason why Jag has different parts, i am going to assume the V8 ones are stronger.

The diff itself is the same 3.31:1 for both V8 & V6 up to VIN M45254, the only differences were ratio's (Mexican auto's got 3.58:1, manuals got 3.07:1)

I can't really comment on the Lincoln stuff, the assumption is that the diff is identical, not sure about the half-shafts.

 

Thank you Cambo

Will have see what I can find out on the axles for the Lincoln LS and/or keep searching for 4.0 S-type diff and axles.

 

I have my reservations about an early model S-Type differential because they may have an issue with defective bearings. I had a 2005 S-Type that I had replace the differential due to a defective bearing. It was a design flaw that was corrected around 2010. The problem also affected the 2007-2008 XKs because they used the same differential.

 

Hardly any complaints about bearings in the pre 2002 diffs, the 2006 onwards yes there was a campaign to change them over, lots of issues.

 

I just stumbled across a post on another forum stating that the STR, XJR and Super V8 have solid rear driveshafts, the other models have hollow ones.

Since there is a different part number for the pre-2002 S-Types for V6 or V8 driveshafts, I wonder if the 4.0L ones are solid, and the V6 ones are hollow?

If that is the case, then I don't see a problem putting the 4.0L driveshafts in an XJR.

 

Will I need to replace my shafts* when I put the Quaife in?

What else needs to be replaced?

**That was not a sexual innuendo..

 

No the Quaife goes straight in to the original XJR housing, no need to change anything else except for the bearings that go on the Quaife center, and the shaft seals.

Or if you want to rebuild the whole diff when you're at it, then you also need the bearings & seals for the pinion, and don't forget the pinion nut & collapsable spacer.

We did try to identify all the bearings/seals/pieces here https://www.jaguarforums.com/forum/x...arings-102296/

The idea of going to the 4.0L S-Type diff/shafts is that you have a lot more choices for LSD's. With the 4.2L diff you have Quaife or nothing. With the 4.0L diff you can choose clutch-plate LSD's, Torsens, etc.

 

Yay! Thanks for the link.

I will rebuild it all. No point going in twice.

 

Cambo,

is there any other difference in the axles other than being solid?

I see that the 2003 and newer s-type rear diffs with the 4.2 have 2:87 gear ratio. If you didnt want to change the ratio, would it work with a 8.8 LSD?

Woodford Jag

 

To be honest, I don't see the change to the 4.0L S-Type diff driveshafts being economical unless you are interested in changing the ratio, or unless you are dead-set on using a different style of LSD than the Quaife.

Yes the 4.2L cars use a 2.87:1 ratio, whereas the 4.0L was 3.31:1

With the Quaife you can fit an LSD directly into your existing 2.87:1 diff. But you are looking at $1600 USD + shipping from the UK (another $150 ?) for the LSD alone. If the bearings/seals are another $200 then you're not far from $2K just in parts.

If you go for the 4.0L diff & driveshafts, and change to the 3.31:1, then you need to buy the diff $300?, the driveshafts $200?, an LSD $650 (Ford Motorsport Torsen) plus bearings & seals, again $200 so probably $1350 in parts. Then you need to talk to MoscowLeaper about programming for the new ratio.

If you go for the 4.0L diff & driveshafts, and want to keep the 2.87:1 then it's the same parts list as above, plus you need to take the ring & pinion from your old diff, or buy another diff to take the ring & pinion if you don't want to mess with your original, and then it's a full rebuild so you are looking at additional bearings/seals/parts. It's getting close to the cost of the Quaife option. Unless you can find the 4.0L parts dirt cheap or go for a cheaper LSD like a clutch-plate one, they can be bought new for like $350...but they will probably need maintenance over time.

You also have to think, if you buy a used diff & driveshafts, what about the wear & tear on them, you might want to put new CVs on the driveshafts, you might want to rebuild the whole 4.0L diff.

I guess the labour costs are the same or very close for all three options, just depends on how much you want to spend.

I have a feeling that the 4.0L diff is inherently stronger, having both sides with bolted caps just looks better to me;



But that's not proven, just based on gut feeling.

 

Cambo

Many thanks,

I assume thats the X350 rear diff on the right and S-type on the left. Was the diff used in the S-type R different than the NA 4.2?

Woodford Jag

 

4.2L diff on the left, 4.0L on the right

The 4.2L diff being the same in the X350 and S-Type, the 4.0L only in the early S-Type.

 

Cambo,

Thank you for the Pics and the information, now I see the light. With the Double main caps the 4.0 rear diff is a lot beefier. I guess the answer to my question about the axles, it appears to be the length and possibly input shaft. Now to start scrounging for parts or a complete parts car.

Thank you again. Woodford Jag

 

Why doesn't anybody mention that an XJ has longer driveshafts then an s-type so it is NOT possible to use old type s-type shafts on an XJ. Also the final drive ratio has something to do with the old type being 5speed and the later are 6speed so it is gonna mess up your gearchangingmomenrs and will result in gears under the perfect torq moment More downshifting etc etc.

 

all of this has already been done