So I've been thinking of jumping into the task of trying to find a junked rear end to play with so see what I can find out about getting a LSD to work. My question is does anyone know if all S types had the same rear end housing and internals or just housing or are the housing all different? Like are there different versions as in the STR has a completely different housing and internals then say a just plain S type or are just the internals and gears different. Basically if the housings the same I can just get a junked rear from any S-type build it up and experiment and just drop it in my 05 STR. Anyone know???

 

I'm thinking the same as you. After finishing up on the suspension refit and an ECU tune, I'm gunna fart around with the LSD question. A visit to a Jag dealership parts dept. may bear fruit on this question. Vance, I PM ya a#$ on your choice of lug nuts. Please check it out.

 

Got your PM and replied. I also am gonna start checking some salvage yards cause I got a nice autoshop on base and some time that I can play around with this idea I just want to try and pick up a donor rear end. I just wanna see which S types I can look for to get one. I wish I could visit my local dealer but mine is about 3 hours away.

 

Check with the Lincoln LS forums re: rear-end (same rear).

 

I'll be doing this soon. Got an 8.8 trac-loc from ford racing and now I'm investigating what gears to swap in there while the pumpkin is cracked open. I'm thinking 3.27s

 

3.27:1 is a reasonable gear ratio when considering the STR's ZF trans. 1st, 2nd, and 3rd gears are low. Any lower would cause annoying high engine RPM's during cruise.

 

Thats another thing I was questioning. I saw on there boards that the first gen LS was just a drop in an 8.8 diff bolt up your gears and you got LSD but I guess the second gen had a different rear so they were not able too. So are our rears the same as the first or sec gens?? I think I am gonna have to try and find some in the salvage lots and start taking pics and dig some more.

 

I think it's the castings that are different the internals are 8.8 if I remember correctly

 

Real glad you guys are all tackling this so its worked out before I get to it haha, always one of the things that bugged me about strs. I wanna be able to light up the tires! at one point something like this would be great: (this would be after the kennebell too haha ) http://www.youtube.com/watch?v=KYM1bFiN8X4

 

Any updates on this?

 

It's NOT a Ford rear end. SO it won't be easy. Please read the Lincoln LS boards. The first gen Lincoln LS (2000-2002) has been done without too much problem. The second gen Lincoln LS (2003-2006) can only be done by using the older Gen I stuff or making custom mounting brackets to adapt a Lincoln Mark VIII rear assembly. Both ways have been done and it’s cheaper to swap the Gen I components in.

Another problem that you need to solve. The Lincoln LS can have ANY rear end ratio you want and everything will work OK. The speed is taken from the ABS sensors so your speed will be correct. I found out by accident that the Jaguar S Type will be thrown into limp home mode immediately if the rear end ratio is changed. A poster had the rear end replaced under factory warranty and by mistake Jaguar put a 6 cylinder rear end in with the 3.30 ratio (The STR uses a 2.87 ratio). The car was undrivable because of the gear change. So we still need the programming to be broken so we can adjust this. It does seem that physically the 6 cylinder 3.30 ratio rear end will fit the STR and other V-8 versions. Again what’s NOT known is are there any strength differences that would make the 6 cylinder rear end fail with the higher power of the V-8 or the STR?? I don’t know??

Man do we need somebody to break this PCM open and get access!!!


If you want to play around, a 2003 STR center secton has been on EBay for months. I think it's too expensive. He wants something like $600 for it. Do a search and you will find it. The guy goes by "Euro Chop Shop". He has been parting a 2003 STR for a long time!!
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Someone posted about using a Ford tool that worked (but maybe not to do what would be needed - don't think he tried), and of course avos, Brutal & other techs have a jag tool (IDS) I believe - but again it may not actually do what would be needed.

Er, would it be the PCM or TCM or both? gulp

Any idea how the jag detected the wrong rear end? I suppose it COULD look at the rear ABS sensors but does it? (Or it could be the ABS module flags the "error" and then the PCM goes into limp mode because of that. But does anyone know?)

 

I've been trying to bust the PCM open since I got the car, and even involved SCT and ProTune. we keep hitting walls.

I've emailed EuroToys to ask how they are tunning thier PCM's and as expected no reply.

Its not like it would matter if they gave me the name of the software they are tunning with.. Honestly thier "tuned" PCM is no better then stock.

How would the tuner making cookie cutter tuned PCMs take into account my altitude? air density? my exact fuel grade?

All they can do is ball park it, for that cost I'll put that cash elsewhere.

 

I think it measures the speed out of the tail shaft and the input shaft of the pumpkin,

 

Pardon my ignorance and that I use a different version of English but is the tail shaft the one that exits the ZF (or what)?

Pumpkin is that large orange squash used at Halloween, right? OK, what else is it?

Ahhh, found it: the diff (housing). There's no sensor there, is there? So it can't be monitoring that. Or did I miss the sensor?

 

Yes, it has something to do with how Jaguar monitors more things than the Lincoln LS does. I know both cars can detect incorrect gear ratios in the transmission. So they can detect slippage and set the proper error code for that.

The Jaguar dealer found the problem because the 6 cylinder rear end has a different part number. I don't think the fact the car went into limp home mode helped any with what the error was?? The guy it happened to said the dealer did all the repairs and troubleshooting under warranty. He found out because they had to order the correct parts in and that caused a delay in getting his car back. So he asked why.
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In the ZF manual posted somewhere around here I know there is a sensor on the tail shaft, or output shaft. I dont have the JTIS here at work, but I though I read somewhere that the final drive speed is measured against tail shaft output speed and if the values do not match in ratios you get the limp mode.

So Im curious as well if its using both ABS sensors in the rear since the car will activate the dsp and the tranny will change profile if both ABS sensors differ in speed.( It thinks its turning)

 

Yes, an LSD would mislead the DSC (er, right?) so you'd have to provide tweaked (fake) rear ABS sensor readings, I think. Maybe just copy the fronts? If you switched the signals like that when wanting the LSD to work instead of the DSC (not on the normal roads), but otherwise left them connected, would that do it?

The ZF will, like other auto boxes and OBD, compare OSS (output shaft speed) & ISS (input SS) among other things, I expect. It'll look at slip across the TC (torque convertor), etc, too. But does any of that matter? I don't see why. I'd think the LS box does that (it's normal stuff) but apparently is OK with an LSD.

 

I'm still trying to source a reasonably priced real end still. Trying to hit up the salvage yards around me but there are only open the hours I'm at work so I'm gonna try next week cause I'll be off early a few days. I'll look into mainly seeing if the diff will fit in the pumpkin then I'll work on the gear ratio and such. Thats why I want to source another rear so I can experiment without touching my stock one. Gonna do one step at a time.