Overview of Jag differentials
 

Part 1, part 2 will come when we get to it...

For those of you trying to get your head around which diff is in which car….

Differentials in the late model Jags;

X200, S-Type pre-facelift
X202, S-Type post-facelift
X250, XF all models
X150, XK & XKR alloy body
X350, XJ alloy body
X358, XJ alloy body facelift
X351, New XJ
X152, F-Type

Note that the “Gen” naming is not official and is carried on from the Gen1 & Gen2 nomenclature

Gen1

https://dl.dropboxusercontent.com/u/11575086/Gen1.png

Ford / Visteon 8” unit, used in the S-Type and the Lincoln LS (also Thunderbird)
Equal length driveshafts, symmetrical diff housing

X200 S-Type, up to M45254 (2002MY)

3.07:1 (manual trans)
3.31:1 (automatic)
3.58:1 (Mexican models)

No LSD option from the factory, but the regular Ford 8.8” center bolts in without modification.
Some X202 S-Type owners have fitted the Gen1 housing and driveshafts, along with a Ford LSD.

Gen2

https://dl.dropboxusercontent.com/u/.../Gen2_Gen1.jpg
Here you see a Gen2 on the left, Gen1 on the right.

Ford / Visteon 8” unit, used in various models
Unequal length driveshafts, offset diff housing

X202 S-Type, from M45255 – N52047
X350 XJ, up to H31470
X250 XF, up to R41865
X150 XK/R, up to B32752 (3.5/4.2L only)

2.69:1 (2.7D manual)
2.87:1 (4.2L in XJ & S-Type)
3.07:1 (2.7D auto, 3.5L XJ, 2.5+3.0 petrol manuals, XF 4.2 S/C)
3.31:1 (2.5+3.0 auto, XK/R 4.2 [S/C & N/A], XF 4.2 N/A)

No LSD option from the factory, only aftermarket solution is Quaife ATB (Ford 8.8” doesn’t fit)
See as per Gen1 section it may be possible to fit the Gen1 into a Gen2 car but you need to change the driveshafts and also the ratios.

Gen3 Non E-Diff

https://dl.dropboxusercontent.com/u/11575086/Gen3.png

Complete re-design, internals TBD
Different flanges & driveshafts to previous generation

X206 S-Type from N52048
X358 XJ from H31471
X351 XJ from V00001 (2.0L, 3.0L N/A, 3.0L Diesel, 5.0L N/A)
X150 XK from B32753 (5.0L N/A only)
X250 XF from R41866 to R47153 (all XF engine options incl 4.2 S/C) & from R41754 (all non-S/C)
X152 F-Type from (3.0L S/C non-S)

2.69:1 (2.7D manual)
2.87:1 (4.2L in XJ & S-Type)
3.07:1 (2.7D auto, 3.5L XJ, 2.5+3.0 manuals, XF 4.2 S/C)
3.31:1 (2.5+3.0 auto, XK/R 4.2, XF 4.2 S/C)

The F-Types without E-Diff are;

3.15:1 V6 non-S, 8-speed (open)
3.31:1 V6 non-S, 6-speed (open)
3.31:1 V6S, 6-speed & 8-speed RWD (Torsen)

No LSD option except for the F-Type V6S which has a Torsen, apparently fits in the same housing as the other Gen3 diffs, supplier & details of the LSD center is TBC…
Theoretically the Torsen from the V6S could be fitted into other Gen3 non E-Diff housings

Gen3 E-Diff

https://dl.dropboxusercontent.com/u/11575086/Gen3e.png

Similar to the Gen3 but with the E-Diff option

X351 XJ, from V00001 to V58602 (3.0L S/C and 5.0L S/C only)
X150 XKR, from B32753 (5.0L S/C only)
X250 XF, from R47154 to S61361 (3.0L S/C and 5.0L S/C only)

2.56:1 (XF and XJ 5.0L S/C with 8-speed auto)
3.31:1 (XF, XK & XJ 5.0L S/C with 6-speed auto)

E-Diff is electronically operated LSD.

Note that the XJ from V58603 and XF from S61362 has a new version E-Diff with 2.56:1 ratio in conjunction with the 8-speed transmission but does not appear to be Gen4 as per the F-Type

Gen4 E-Diff

https://dl.dropboxusercontent.com/u/11575086/Gen4e.png

Similar to the Gen3 E-Diff but with different mounting of the E-motor, probably other changes

X152 F-Type, from (5.0L S/C & V6S AWD)

2.56:1 (F-Type V8S, R, RWD & AWD)
3.31:1 (F-Type V6S AWD)

E-Diff is electronically operated LSD.

Some nice cutaway pictures of the F-Type E-Diff here
http://www.motorauthority.com/news/1083826_2014-jaguar-f-type-differentials-electronic-aids-30-days-of-f-type

Summary

All N/A cars have open diffs
All 4.2L S/C cars have open diffs
All 5.0L S/C cars have E-Diffs
The 3.0L S/C XF & XJ have E-Diffs
The 3.0L base model F-Type has an open diff
The 3.0L S model F-Type has a Torsen LSD
The 5.0L F-Type has a different E-Diff to the XKR, XFR & XJ

Nice post Cameron, part 2 will be a good addition I'm sure.

No doubt you'll FAQ it and add it to the database?
Thanks in advance Cameron

That's some work!

Having trouble editing the OP so some corrections and additional information here;

The Gen1 & Gen2 are a Ford Visteon differential, not Valeo

The Gen3 & Gen4 as well as the E-Diffs are made by GKN Drivelines in the UK

GKN Driveline Media Centre : **Jaguar** reveals new **XKR and XFR** with GKN Driveline?s **Electronic Torque Manager ETM®** & http://media-centre.gkndriveline.com...R_5_Mar_EN.pdf

E-Diff utilises the Electronic Torque Manager ETM from GKN

The "Torsen" in the F-Type V6S is probably the GKN "Helical LSD" since Torsen is a brand name owned by a Japanese company now. Helical LSD - GKN Driveline

Now, i wonder if GKN would sell the individual spare parts and LSD centers...

They may sell to gearbox specialist companies. Such a company would maybe need detailed parts data. Appearing to be such a company may need letterhead or the like. Doable...

Now the main purpose of my putting all this info together, a cheaper/easier way to fit an LSD to your car.

A big thread on it here; https://www.jaguarforums.com/forum/s...install-86430/

And some important highlights that came out of that thread.

1. The only off-the-shelf LSD to fit the Gen2 Ford/Visteon diff is from Quaife
2. The Gen1 Ford/Visteon diff can be fitted with a Ford 8.8" 28-spline LSD
3. The Gen1 diff and driveshafts are a direct bolt-in to the Gen2 S-Type R

Additional information;

The last iteration of the S-Type R, and the X350 S/C up to H32732, have exactly the same diff and driveshafts.

The 4.2L X150 XK up to B32752 uses the Gen2 diff and also had these exact same driveshafts, although the diff was a different p/n because of the ratio being 3.31:1 like the 3.0L Auto S-Type. The p/n of the XK 4.2 diff and the S-Type 3.0L diff is the same.

The XF up to VIN R41865 also has the Gen2 diff and has the same part numbers for the diffs as the S-Type. However the driveshaft p/n for the Gen2 on the XF are not the same as the S-Type, X350, or XK. For whatever reason.

But, when the GKN diff was introduced as a replacement for failing 8" diffs (TSB JTB00175), the driveshafts are the same p/n for the S-Type, X350 XJ, and XF.

Summary;

Take a diff from a wrecked pre-2002 S-Type (engine/trans changes ratios, see below)
Take driveshafts from a wrecked 4.0L V8 S-Type (the V8 driveshafts are stronger?)
Fit a Ford 8.8" 28-spline LSD to the diff
Bolt in diff and driveshafts, with a cheap-enough LSD option

All S-Types (that have not been updated according JTB00175)
X350's up to VIN H32732
X150's up to VIN B32752 (4.2L)
X250's up to VIN R41865 (4.2L)

BUT, you have to take care that the diff ratio is kept the same, or you get the car reprogrammed for the new ratio.

The pre-2002 S-Types had the following ratios;

Manual Transmission 3.07:1
Automatic Transmission 3.31:1
Automatic Mexican Specification 3.58:1

The newer cars need;

S-Type R & X350 XJR needs 2.87:1 (swap gears or reprogramming needed)
X150 XKR 4.2L has 3.31:1 (no problem)
X250 XF 4.2L N/A has 3.31:1 (no problem)
X250 XF 4.2L S/C needs 3.07:1 (swap gears, or get donor diff from manual S-Type)

If you have an X350 XJR newer than VIN H31470 you can still do this conversion but you need to get a propshaft/driveshaft/tailshaft from an earlier X350 XJR as well.

Ditto if your S-Type, XK or XF was treated to a new diff under the TSB JTP00175, you will also need a propshaft/driveshaft/tailshaft from an earlier model.

This is all theoretical at the moment, but in the next few months I hope to have done this conversion on my own car.

Attachment 208084

Thanks for this post. You have inspired me to try a ratio change on my 2014 v8s using the v6r awd ring and pinion. I think the change will really wake up the car.

I had not considered a ratio swap on F-Type (or other 5.0L cars), for a few reasons;

1. The lack of re-programming. Without reconfiguring the car for the new ratio it will throw up codes & errors.

2. How to disconnect the E-Diff so that there are no error messages?

3. Is the V6S diff capable of handling the torque from the V8?

Until the electronics/programming is addressed, you can't really go further.

I was assured the programming is doable. I can't imagine there is much difference between the e-diff in the v8s and the e-diff in the v6 awd model other than the ring and pinion. Usually lower gears (higher numerically) are stronger. Certainly they don't have to convert thenpower into as much forward motion given the greater mechanical advantage. If the two models each have an e-diff but the lower hp model has a different case holding its lower gear set that just seems like a waste of engineering resources to me but I suppose it is possible.

I am going to start on the mechanical side and if the change is doable physically Inthink it is worth a shot.

Thanks for the post and reply.

Ah right the V6S AWD with E-Diff...., for some reason I was thinking you wanted to ditch the E-Diff and put in the Torsen from the RWD V6S.

You might have to wait a while until the spare parts listings are available for the 2016MY, but if the rear driveshafts from the AWD V6S and the RWD V8 are the same length / part number, then mechanically it should be an easy swap. So long as there are no electronic differences between the E-Diff mechanism, could also be plug & play.

The diff ratio itself is programmed in the cars VID block (or maybe with the new models it's the CCF like the Land Rovers) in any case you'd need a wizard who is able to modify that data. There is a forum member working on such things, not sure if he's up to the F-Type yet...

Thanks for the quick reply.

I agree on waiting for parts numbers and your thoughts on half shaft or rear drive shaft part numbers seem like a good way to verify compatibility of the cases.

The parts should not be prohibitively expensive for the potential benefits. I would rather explore this than grinding my supercharger snout for a smaller pulley.

The car seems like it has way too much gear in it as delivered. Probably another CAFE tweak for a half an mpg.

It's in CCF. Will visit a dealer this week and try to change a diff ratio on a test drive, to see if it will throw an errors :)
Actually new cars are a way easier to modify than the older ones. All you need is an engineering password and some knowlage ;)

Which diff is in the 03-06 XKR? And what is the easiest way to swap to taller gears in this diff?

How did that experiment work out?

That was going to be the Part 2 that I never got around to...

The X100 XK and X308 XJ have the same diff, called the 14HU, as you know, no factory LSD option on those cars.

The 14HU is similar but not the same as the 15HU used in earlier models such as the X300, XJ40, XJS. The 14HU has a bad rep for being fragile, the 15HU is claimed to be over-engineered.

If you want to fit an LSD to a 14HU then there are a few options; Gripper (UK), Quaife (UK), OS Giken (JP) maybe others.

If you want to change ratio's in a 14HU then it's possible, but for the effort involved most people get hold of a 15HU assembly out of an X300 and go from there. Since the X300's often had LSD's from the factory (Powerlok, clutch-type) and with a bit of massaging and parts swapping you can bolt them in.

I have never owned an XK8/XKR or an X308 XJ so I never looked that closely into it, but that's basically what the people here on the forum have said.

Thanks Cambo! Do you know who may have successfully completed this swap? I found a few instances of swapping the diffs on 4.0 X100, but still haven't found a concrete reference of anyone doing this with the 03-06 4.2.

As far as I know the diff itself is the same unit between the 4.0 and 4.2 XKR ?

A few have done it, JgaXkr is the one that jumps to mind, some X308 XJR guys have done it too.

Correct, it is the same unit for all of the X100 series, 4.0 or 4.2L

Add the Lincoln LS 2003-2006 to the Gen II dif listing.
The 2000-2002 LS used the Gen I set up.
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Ok, I have been researching using a Torsen 2R. You just made this a TON EASIER.
1. Quaife is a good product but expensive and requires pulling the TRAC Control fuse.
2. The MM Mustang IRS TORSEN IS CHEAPER AND IT HAS 2R that's perfect.