tijoe, thanks for studying the Lincoln LSD swap. I think the difference between the Gen 1 and 2 pumpkins is that the Gen 2 is offset a bit causing one of the axels to not slip entirely into the carrier. Our concerted efforts will bring a LSD to the STR.

 

Interesting.
What is offset? The carrier in the housing? Are the axles the same length on the LH and RH axles?

 

This is what I've been told by those who have done this upgrade to their LS, so the S-Type setup should be the same. (YMMV) Here is a pic with the Gen 1(right) & Gen 2 (left) rear diff carriers. The Gen 1 has the Trac-Loc installed. On the Gen2's the carrier is narrower, the center line of the pinion is different, they used different axle half-shafts, and different diffs. These parts are generation specific. Second pic is a comparo of the stock Gen1 (left) & Gen 2 (right) diffs. A Trac-Loc will not fit into the Gen 2 carrier due to the Trac-Loc's larger casing, so any LSD you put in will have to be modified (pic 3). The DEW98 ring gears have the gear size of a 8.0 and the bolt pattern of a 8.8. Any 8.8" 28 spline Mustang LSD unit will fit the Gen 1 housing without modification. Oh, and the carrier shim kit for the 8.8" rear end is identical to the 8.0". That's all I can remember right now.

 

Some of the Quaife models have engineering drawings on their site. If you poke around you might find the one you need. It will show at least some critical dimensions that you can use for comparison purposes.

 

Just search on the quaife site as Plums mentiones. The QDF3W is for the aluminium XKR, which is the one that is the close fit. The QDF5W is for the classic steel bodied XKR, which will not fit.

 

I wish someone in the USA just offered an exchange service to do this modification. For one of my previous cars, Q45, there was a performance company that changed the ratio for better acceleration. You simply shipped them the diff and they had it back in a couple of days.

I wonder if there are any companies out there who already perform this type of service for other makes and might be willing to take this on?

Most of us don't even have the facilities or the knowledge to do this properly the first time around but we can write checks!

 

Just to confirm that, the 4.2L Alloy XK has the exact same part number for the diff assembly as the 3.0L Auto S-Type. Straight swap

 

Panthro! Thanks for posting the images.

What I wonder is what Ford/Jaguar engineer/group made the lame decision to make a unique unequal length housing that requires non-symmetric axles. It couldn't have been to reduce costs! If they had stuck with their common 8.8 design and only changed the housing, everyone would have been much happier! It was bad enough that they made a 8.0 hybrid from the 8.8 for the LS and Gen1 S-types. No!!!, they had to make it even more unique for the next generation Jaguars.

This give me a little more motivation to figure out how to put a Cobra or Explorer 28 spline LSD differential in the STRs. But I suppose that if you have to change one axle, I might consider going with 31 splines. More common these days. Lots of easily customized axles for IRS swappers.

Attached are images I found online of an explorer IRS differential. If the cover off of a GEn 1 S-type diff. would fit, and the mounting boss just happens to be the same distance from the axle centerline and pinion centerline, then perhaps a swap might be easy and straight forward.

 

Explorer diff is the same as the Mustang; the carrier is not though. Just has to be 28 spline to match the stock axles. Just as a side note, the LS guys/girls also have a 3rd swap option, albeit it does require more fabrication. The Mark VIII diff carrier fits the stock cover, but the case requires custom front mount & a custom drive-shaft. The best part of this swap is it opens up a multitude of different ring/pinion options since it's the same gear-sets as the Mustang. Now if somebody found a way to reprogram the ZF6HP26 TCM, you could conceivably get the same kind of rear-end combos that they put on the Boss 302 since it basically uses the Ford version of the same transmission (6R80). AFAIK, that kind of swap is currently in the works by the SN197 crowd, so the light at the end of the tunnel is getting closer. (I'm on alot of forums ya know...lol!)

 

Bob, the Lincoln LS forum mentions an outfit that sets up differentials shipped to them.

 

I thought that all Ford 8.8 Differentials had the same 10-bolt pattern on the back of the pumpkin. I believe that the Cobra and Mark VIII use the same basic housings, The Explorer/Mountaineer pumkins are different in that they have only one front mounting boss, (like the S-type 8.) but the rear cover bolt pattern is the same for all three.

Does the gen 1 S-type rear cover have the standard 8.8 rear bolt pattern?
Does the Gen 1 and Gen 2 covers have the same frame mounting pattern?

If this is true, would you be able to bolt a Gen one rear cover on the 8.8 explorer pumpkin?
Might the Explorer 8.8 mounting boss line up the same?

All I have are pictures, so I can't tell if this might be true.

Tomorrow I will crawl under my 2004 STR and 2000 S-type to try to tell if the sub frames have the same differential mounting points.

Her is an image of the Mark VIII 8.8 differential.

 

This idea pops up repeatedly on here and if it were a simple exchange that was proven to work well then I'd be interested.

If there's interest why has no one contacted them?

Anyone know?

 

Bob, we've likely reached the point where we're all collaborating to bring a proposed LSD to the assembler for specing, modification, then assembly. Here is the link to DTS in Warren Michigan. http://www.drivetrainspecialists.com/ They will take our carrier and properly fit a LSD. I'd allow them to figure what differential would work best. I called and left a message that basically described our situation and we'll send our differential for a LSD conversion using stock ring and pinion.

 

The reason Ford changed the rear end and axles for the 2003 and up Lincoln LS and Jaguar S Type was because of customer complaints of noise and vibration. The different lengths and non-symmetrical setup is much less prone to resonate.

The first gen Cadillac CTS-V also suffered from this along with massive axle hop because that car was a 6 speed manual only. The second gen CTS-V rear suspension was modified very similar to what Ford did on the S Type/LS.
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Clubairth1, great input on why they changed the design.

I crawled under my 2004 STR and 2000 S-types and made a list of the differences.

1. Different sub-frames
- The Gen 1 Sub-frame looks better built and more robust than the GenII sub frame.
- Perhaps the Gen1 sub-frame was too stiff and added to noise and vibration.
2. The sub-frame mounting locations to the car body are the same.
- The 2004 STR has extra plates over the front sub-frame mounts and use a different mounting bushing
3. The upper and lower A-arms appear to be the same between cars.
(Shocks and springs look to be the same)
4. We all know that the hub carriers are different for the Earlier STR's to add the Parking brake.
5. The toe links look to be different and have slightly different mounting positions between the Gen1 and GenII sub frames. (The hub carrier toe link mounting arms are about and inch longer on the STR versus the 2000 S-type hub carrier.)
6. As has been discussed, the Gen1 and Gen2 differential carriers are different between these cars. But, it looks like the front mounting location is the same between the 2 carriers. Bbut, as far as I could tell, the rear housing mounts are at a different height, but close to the same width.

I can see two approaches for adding LSD to the Gen1 cars. Put in the LSD unit as has been proven to work, and be stuck with the stock gearing, (inexpensive) or use an 8.8 differential carrier and adapt it to fit the subframe, put in new axles and perhaps have the drive shaft modified as well. (Expensive, but will handle a lot more HP and perhaps be more reliabile)

For Gen2 cars, Lets hope that DTS finds a LSD that can be fit into the carrier, or if you want LSD in your STR, you may have to either put in a Gen1 carrier fitted with a LSD, or fit in an 8.8 IRS LSD unit. $$$

 

Joe, thanks for specing the differentials. Bet we're all hedging DTS can pull a rabbit out of its hat. They'll need one of us as a test mule.

 

Sorry to be ignorant about this but would it be possible for someone in the know to post a summary chart of which year cars had gen 1 vs gen 2 or is by vin# with in the years as well?

From what I am gathering the earlier diffs are prone to a noise.

I'm not sure I'd be willing to go backwards in order to gain a LSD?

Thanks

Bob S.

 

While looking at the gen 1 and gen 2 carriers, I noticed a difference in my 2004 STR versus my 2000 S-type where the mounts for the toe-arms/toe-links are different. I am going to start a new thread to ask some technical question regarding toe-in and toe-out or the rear ends. I am sure you will all see the post.

 

Yes.
Jaguar S Type Gen I - 1999-2002
Jaguar S Type Gen II - 2003-2008
With another smaller update for the 2005-2008 cars.

But as you know Jaguar goes by serial number more than year of production like Ford does. Generally the cut off between the S Type Gen I and Gen II is serial M45255. I have also seen M44998 used. There are a few 2002.5 STR's in the UK too. The Gen II is sometimes known as the "Face Lifted" S Type.

Lincoln LS Gen I - 2000-2002
Lincoln LS Gen II - 2003-2006

Both cars suffered from "de-contenting" as Ford started removing standard options or adding them to the extra charge column after the decision was made that both cars would be dropped and not further developed. The LS lost things like rain sensing wipers, A/C seats. Puddle lamps in the door mirrors (Both of which should have been installed in the S Type too! They are great!). The STR lost the expensive Brembo brakes after 2005.

No the earlier diffs were not prone to noise. Both generations have had a small number of complaints for this. Jaguar's solution is generally to replace the entire rear end. Fords solution has been to replace differential bearings one at a time or in the best case at least replace the center diff.

Just another way that shows Jaguar does a better job solving problems for the customer. But Jaguars are more expensive than the LS so I guess you pays your money and takes your chances!

This is where we learned that changing the rear end ratio on the S Type throws the car into limp home mode immediately. The guy had a 4.2L V-8 and the Jag dealer installed a six cylinder rear end by accident under warranty. Again Jaguar uses serial numbers to identify the car and apparently made an error somewhere about what was suppose to be installed in that certain car? Car could not leave the dealership! This also shows that at least from a physical install point of view all S Type rear ends of the same year will interchange.

Tijoe - Just a note. We have found that there are a number of suspension parts that are the same as far as mounting points go. BUT some of them have a SC on the Aluminum forging to denote use on Super Charged vehicles only. Jaguar does not break this out in black and white. So the best method is to use the JEPC and see if the part numbers are different once you determine they are the same geometrically. We also don't know what exactly is different about these parts marked with the SC but the thinking is of course they are heavier duty because of the higher horse power in the STR?
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Avos just wrote me that he personally prefers the clutch-pack differentials (such as the Ford Traction-Lok), and that these work better with the S-Types DSC system. Looking foward to speaking with DTS tomorrow, and will report back to this thread.