Did anyone ask?
You could guess, what's it cost for an XJR, XKR or similar? Heck, what's a new one cost from a dealer?
Besides, you know what they say: if you have to ask you can't afford it

 

I never asked about price since I was more interested on the getting it to work aspect. I did find their site which is paramount performance and they dont have the LSD listed for the S type yet. They have them for the XK's and they are 1560 pounds which comes out too 2490 dollars. That looks to just be the diff so if they have to do stuff to the housing I'm expecting it to be more then that. I know that Quaife diffs are pretty pricey. Seen them for 700 and up depending on what vehicle. So this is definitly something I'll have to wait for. Really wish I could get a spare housing that isnt gonna cost me over 400 so I can experiment with.

 

Here is a link to the Quaife website
http://www.quaifelsd.com/applications.aspx
I looked into this at one point & seem to remember that the new XK diff was the same as the XJ & S Type. For the $1275.00 for the LSD unit anyone who builds rear ends should be able to install or make it fit. You may want to speak to Dick @ Coventry West, he runs the rebuild department. I have had a LSD fitted to my XKR for 3 years now with no issues with traction control. This type of a project is probally going to cost between $2500 & $3000 by the time you are finnished. Remember if you want to play like a sport you have to pay like a sport.

 

Ah, some details - thanks! (Not that I'm going to do this, as I don't have any need or desire.)

 

So true. Especially for low volume cars like these. The market for this sort of thing here in the USA is not it would be for a Toyota, Honda or Subaru. Most likely you're going to be be doing a rebuild at the same time.

Another place on the east coat than can probably do this is Level 10 Transmissions in Hamburg NJ. They can probably spec out a series of option for you.

Shipping a diff from the UK is going to be very expensive. I did one from Germany a few years back (6) and it was as about $375 back then. Then there were the customs fees.

 

Hi all, after a long period my Jag is going to be upgraded.
I have bougth from Quaife a new LSD and with my team we are going to mount it in the next weeks, it depends how much time we will be busy with the racing teams we follow.
I will revert you soon about the outcomes.
The difference we are searching is in post apex acceleration, and in our experience this is the best upgrade you could have to improve the speed out of the curve.

 

I grew up in NY/USA and know very well the advantages of LSD in mud/snow.. Hmmm..I did not know this"post apex acceleration".. Are some folks racing these S-type ?

 

Oooh, keep us informed!

 

Hmm, I see that the catalog from Quaife UK says that model DFQ3W is OK for S-type models 2003-2008. However, the Catalog from Quaife USA makes no mention of S-types.

I have emailed Quaife UK...

 

Wow, thread resurrection....

As some of you may know, I have a Quaife QDF3W in my 2005MY XJR for the last few years, it totally transformed the car, absolutely night & day.

The diff in the XJR is the same one used in the S-Type R, as well as the first of the alloy bodied XK/XKR and the XF

See more info here https://www.jaguarforums.com/forum/j...ntials-134733/

The Quaife will absolutely slip right into your STR.

 

Thank you so much for all that info, Cambo. My 2005 STR is N34544, and I need an LSD more than I need another 200 hp, so a few quick questions...

1.. What does the "m" in QDF3Wm mean?
2.. It seems only a Quaife will do - how and to who do I specify "Gen 2"?
3.. Any other parts needed? Bearings, seals?

My indie will do the work, but it sounds quite straight-forward. Any particular things to look out for?

 

Oops the 'm' was a typo....

Don't worry about the Gen2 bit, that was just to differentiate between the diff in the 99-02 S-Type and the one in the later model (you saw the pic of both diff side by side?)

Yeah if you want to do it properly then you need;

Bearings to go on the Quaife center
Axle seals

You don't need to remove the pinion from the diff to swap the center, and it's probably better if you don't, actually...

We had a thread going with all the part numbers for seals, bearings, etc... i'll have to find it... EDIT here https://www.jaguarforums.com/forum/x...arings-102296/

 

In any curve there are three important points that you have to take care in order to be as fast as you can in turning.
Apex is the middle point, usually is where you start again to accelerate, it is exactly when your body stop sinking and your damper are "re-damping".
With a standard Diff you are loosing traction due to the weight on the exterior wheel only, but with a LSD your car pushes straight and take you out of the curve quickly and faster.
You notice this behavior if you follow a well driven Porsche or Bmw M.
After the curve they spring away from you and you stay there, waiting the traction on your wheels.
This is valid on standard driving or track days.

 

Thanks Cambo, I saw the thread you mentioned. I am not in your techie class, and just need to be sure I have the right parts and a good understanding of the steps involved before I start ordering. Please forgive my ignorance here.

In your recent post you said "Yeah if you want to do it properly then you need;
Bearings to go on the Quaife center
Axle seals".

In that earlier thread you said:
1x Quaife QDF3W LSD center
2x Axle Bearings, Timken p/n LM603049 (race) & LM603011 (cup) also sold as "SET37"
2x Axle Seals, Timken p/n 714569, Ford p/n 2R8Z-4B416-AA, Jag p/n XR821244
1x Pinion Nut, Dorman p/n 81053, this is a "universal nut" same as Ford 8", 8.8", 9"
1x Collapsable Washer / Crush Sleeve, Ford p/n B7A4662A, Dorman p/n 81056
1x Pinion Seal, Timken p/n 3604, Jag p/n C2S1490 rep. C2S52518

If you need to change the pinion bearings, these are Timken p/n NP945727 and M88048 (race) + M88101 (cup)
I since discovered that there are a couple of suppliers offering complete kits for Ford 8" as used on our cars;
Timken p/n DRK311, DRK311B, DRK 311BMK
"Timken Light Duty Differential Rebuilt kits include bearings, seals, crush sleeves, shims, pinion nuts, gear marking compound and sealants that are required to service the vehicle’s unit"

That second list looks more complicated - if I go ahead and just order the Quaife, a Timken "SET37" bearings and 714569 axle seals, are you saying the pinion can be left as is, or should I be getting the Timken DRK rebuild kits?

 

It really depends on the condition of your existing diff and who's going to do the work to fit the Quaife.

Strictly speaking you do not need to touch the pinion at all to fit the LSD center. In which case you just need the two bearings to go on the center and the axle seals. (I wish I had done it this way the 1st time)

If you want to rebuild the whole diff then you need the pinion bearings, pinion seal, collapsable washer and preferably a new nut too. Which is where a whole kit comes in. (here's where I got in trouble because the guy who did my diff the 1st time re-used the collapsable washer, and over-tightened the pinion)

It does seem that the complete kits from Timken do not have the correct bearings for the diff center, perhaps those kits are for the 1st Gen 8" diff from the 99-02 S-Type.

If I were to do it again, i'd leave the pinion alone.

OR

I'd take a 1st Gen diff & driveshafts from a 99-02 S-Type and fit a regular LSD to that assembly. It's been done by guys in the UK, the older setup bolts straight in to the newer cars. And it gives you a greater selection of LSD centers to choose from.

 

Good info, thank you again Cambo. As inspector Columbo would say, just one more thing...

I checked the Timken catalog and found that LM603049 and LM603011 are available as SET35. What bothered me a bit was that this info was in a catalog that dealt with cars 1989 and older, as was the seal p/n 714569.

Is that right? Are these parts really of that vintage? Just want to be sure.

Finally, if there's a need to overhaul the pinion assembly later on, can I get parts from Jag, or is Timken the only supplier of the kit?

 

The only diff spares available from Jaguar are the seals (and I found it easier to buy the seals from Jaguar than from any Timken suppliers).

Bearings you can only go aftermarket, nothing from Jaguar. Although Koyo also supplies the same bearings too.

The LM603049 and LM603011 could be from older vehicles, maybe they are shared with the 8.8" Ford diff? I don't know for sure.

 

So, are those bearings in SET37 as you say or in SET35?

The Timken catalog describes SET35 as "LM603049/603011"
.....and the catalog describes SET37 as "JRM3939-90U08".

Hope I have not reached the limit of your tolerance - can't imagine how long it must have taken to pull all this info together.

 

It was a while ago that I put that list together...

The "set" is probably wrong. But the individual part numbers were right.

 

We are waiting to get the part from Quaife
But we are confident that won't be worse as doing this kind of mod in BMW or Nissan.
We are getting the bearings from SKF catalogue every time because they are the biggest automotive suppliers for bearings and we have found everything we need ( except some parts that they produce exclusively for BMW Motorsport and you have to call BMW to get them)
We will keep you informed