So what's the deal with the 2005-2008 update?

Anyone know and does it affect this project?

Maybe this is what I mistakenly thought was the Gen I to Gen II change and was about addressing noise?

 

Yeah I'd like to hear more details about that and I am interested in the real world effects that this sort of change would have on the DSC which I find rather crude right now.

He''s be an interesting one to have elaborate on this subject.

It's not just dry street traction/performance I'm concerned about.

 

The 2005-2008 update was pretty much just cosmetics. We did get some more changes later on. The big one was replacing the Brembo’s with the standard single piston brake system for 2006-2008 on the STR.
.
.
.

 

Today I spoke with Eric of DTS. We spoke for a few minutes. He's somewhat familiar with the Lincoln LS 8" rear and was sort of surprised Jag did something different. I reminded him the STR has 400 chp and would need more beef in the rear. He mentioned it would all come together once he has our carrier in his shop. He has my cars VIN and will call me soon. I also directed him to our thread. So, let's see....

 

Please remind them that it's not just the STR, it's also the 4.2L X350 and 4.2L X150 that will benefit from this sort of conversion kit.
And there are STR, XJR, XKR enthusiasts all over the world who are interested in this

 

Yep Cambo. I let him know that the V6 and V8 have the same rear but with different gear ratio, and different Jags models are interested in a LSD.

 

Eric of DTS called today. He contacted Ford and Jaguar. Ford gave him some info. but nothing from Jag. He needs info from differential cover. Is there any numbers, names, etc. Tomorrow I'm taking a pic of the differential cover. He said if it doesn't have Ford stamped on it, it may be a Dana rear. Of course he said if he had a carrier with him it would be easy to identify and likely fit a LSD. Eric also said one way to decipher wether Ford or Dana is to order a side seal of the carrier (where axles pass through). If it crosses as a Ford part then we have a Ford differential. He recommends a non-clutch differential, as the clutches will wear. If I soon put my STR up for the winter, I will have the indy Jag mechanic remove the differential and ship it to DTS. Any info guys?

 

Yes. See pictures below. They contain all the numbers from a 2003 STR.
.
.
.

 

Way to go tbird! Spoke to Eric (DTS). He'll visit this thread to garner the info. off tbirds differential. Again, the V6 and V8 use the same differential thus the same LSD. Stock ring and pinion must be retained for both.

 

No problem. The pictures are from a 2003 and I have a 2005 STR. But I can't find any differences other than the gear ratio for any S Type differential. Or Lincoln LS. The two cars have different ratios so if we ever get programming to allow us S Types to change the rear end gear we will have a 3.58 ratio option from the LS. This ratio on a STR would be a BIG improvement over the stock 2.87!

In fact Jaguar did something similar with the XF but only went to 3.31.
.
.
.

 

Spoke with Eric again. He said we have the same 8" Ford differential as the Lincoln LS, except our rear cover has cooling fins. He feels 95% that we can use the 8.8" Auburn, Traction-Lok, or Tru-Trac differentials, which he recommends over the other two due to its low cost and stronger build. The cost would be: $240 labor + $173 new bearings all around + $445 for the Tru-Trac differential= $859 plus tax. If four or more send their carriers he'll likely take off nearly $100. Wonder if we can purchase Tru-Trac for less than $445? Eric has the Lincoln LS carrier and is going to try to set it up as a LSD. This way we don't disassembal prior to definitely knowing this will work.

 

Make sure he is aware the gen1 and gen2 diffs are different, and the 03+ STR's use the newer gen2 design. I don't think those are as compatible with the 8.8...

If this confirmed working for an 03 STR pumpkin, I will strongly consider sending them mine over the winter...

 

Thanks for the Generation 2 reminder. I'll call Eric of DTS and bring this point up.

 

I just poked into this thread for the first time. Great Job you guys! Thanks to y'all who've carried it this far.
I don't know what I have to contribute, other than a big "I'm IN!" once it's confirmed doable & affordable (as it seems it'll be)

I'll continue to watch closely, so that if three's something I can help with, I'll be timely about it! :-)

Looking forward to updates.

 

Having done this to a couple of my other cars, one a track car and the other a street car I'd be concerned about the gas mileage on the street car with a 3.58 if we're currently running a 2.87. That's going to require software changes too. Yeah I know it's no gas miser anyway but frankly it's fast enough already for my purposes. My track car went from a 3.31 to a 3.90 and 0-60 went to 4.1 but the car also gets caught out at redline in a number of situation at the tracks I frequent so I bout a different ratio diff to swap in.

I just want better and smoother control which I'm hoping will we'll get? What has AVOS had to say about how the switch to a LSD has performed in that regard?

Any surprises pleasant or otherwise?

 

It won't be a problem with the ZF 6 speed. I would guess your other car was only a 4 speed manual or 3 speed auto. We have such an overdrive ratio in the ZF I don't think you would see much difference.

I know the 2009 XF (with the lower 3.31 ratio) fuel mileage is still rated almost the same as the old S Type with the 2.87 ratio. They both have the same 4.2L and 6 sp ZF transmission.

I guess it will take some real on the road numbers to know for sure.
.
.
.

 

The beauty of the late model Jags is that they have electronic differentials that swap to and fro low and high ratios. IMO, the same 3.30 found in the V6 would serve an all around purpose. Last night some ******* slashed all four tires on my 03 STR while it was parked behind my office. So between mitigating (insurance vandalism claim) that I'll call Eric at DTS to remind him we have the Gen. II 8" rear.

 

Spoke with Eric regarding Gen I vs Gen II 8" carriers. He isn't aware of any physical differences. Does anyone know the physical differences between the two? I told him there was grinding down of our carrier to fit the Quaif differential.

 

The electronic differential does not contain different gear ratios. All it does is switch from an open diff (0% locking) to various amounts of locking, up to 100%. The amount of lock up is controlled by the PCM electronically. This gives the LSD a very fine control that you don’t have with the mechanical versions.

Most LSD are mechanical and go into action when one tire spins more than the other. Regardless with what’s happening to the rest of the car.

Well they won't interchange with each other so he better keep looking!!

.
.
.

 

Guys, forget about a ratio swap. I've been down every avenue to find someone who can reprogram the TCM, even ZF themselves, and everyone said no.

Now, getting back to the LSD. As previously mentioned I know a guy in the UK who had the Quaife unit installed in his X350 XJR, no grinding/machining needed.

The difference is which centre you get. The QDF3W is the one to suit the STR, X350 and early X150's. The QDF5W is for the earlier X100 & the X308.

We saw in the photos in Panthros post HERE that the diff center in the Gen2 is a bit shorter/slimmer than the Gen1, this is the problem why the internals are not a straight swap.