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@lizzardo Steve, I have a 3.31 rear unit on hand that I can upgrade it with a Quaife ATB unit for you, and I would ask that you send your old rear diff back to me once it is swapped out.
So you don't need to procure a spare diff of the right gear ratio, but if you do, it helps with schedule flexibility and gives you an extra rear end for spare parts or future use.
That's exactly my plan. Without the shop facilities I used to have, it might be a while before I actually get to the swap. I don't want to hold up the pipeline while I get my act together.
@lizzardo Steve,
I can summarize the differences that I have seen between various rear differentials. (DANA 44 AdvanTEK type, late model Jaguars)
the V8 F-Type cars have the e-Diff, which is a different beast than the simpler rear diff found in the 6 and 4 cylinder models.
there are no external differences in the MT and AT rear differentials (same castings, same seals, same plugs) , but there are some internal differences due to gear ratio selection.
The axle half shafts are a different part number on the MT cars vs. the AT cars, the only difference seems to be the mass.
Some Jaguar models (XE/XF, F-Pace) feature a rubber dampener on the input yoke to the rear differential, where the F-Type does not feature one, a minor tweak.
@dangoesfast I see that you have an XE-S sedan. Do you know which rear diff gear ratio you have? Is your car AWD or RWD?
Can you get a picture of the tag on top of your diff?
Note: I first wipe off the dust and dirt from the top of the diff unit, then use a borescope to peek at the tag.
I haven't checked yet - I knew I wanted to upgrade the diff, but I haven't done all of my proper research yet. I'll get her up on the hoist in the next few weeks and see if I can find the diff tag.
Originally Posted by HermanWiegman
I have seen both the 2.73 ratio, and the 3.23 ratio used in the XE sedan.
The good news is, that Quaife is making a shim that fits the commissioned ATB with the 3.23 gear set, (which your V6S model probably has).
If you want to stay with a friction disc LSD (as found in the F-Type V6S models), I can offer you a rebuilt LSD diff carrier from a F-Type V6S application.
It should swap right in to a rear diff with the the 3.23 gear ratio set. (The 3.31 and the 3.23 ring gear sets are both based on the same gear backing interface dimensions).
Oh that's fantastic, great to know you can help with both options! Would the rebuilt LSD have new friction plates?
Herman,
Keep us posted on the progress. Still plenty for me to do on the FJ40, so no big rush.
Anyone want a complete OEM limited slip differential case assembly? (only 41k miles in excellent condition). I extracted it from the donor diff that will receive the Quaife.
There is a group of seven of us who have committed and put in the down payment.
I have wired the down payment to initiate the build of the Helical ATB's (and spacer rings) with Quiafe.
The total wire transfer to Quaife came to $3,984.08 with fees and exchange rate.
Thanks for your patients as I lost a bit of momentum in August. But we are back on track to have units made this year. @Unhingd has already sent me his "donor" rear diff unit (with friction LSD removed), so it will be ready for the installation of the helical ATB. @Dan Wink may follow soon.
You can send your "donor" to my RI address if you want to get ahead of the rebuild curve. (95 Preservation Way, Wakefield, RI 02879)
I have some core units at my house that will be upgraded to the Helical ATB and shipped out to those who do not have a "donor" rear diff, in exchange for their OEM diff.
But I will need an indication of who is ready to do the rear diff swap in their cars, vs those who are planning on doing the swap some time in the future.
This will help us be efficient.
So far, I have enough 3.31 gear sets to go around, and one 3.23 gear set for @Naif Kasheqri 's base AT 3.15 car.
The instruction set for doing a swap is still in development, and I will try to share a PDF draft here... (if the forums takes PDF downloads).
I've got a BA unit from a 6MT car that should be here Wednesday. I'll turn that around to you as soon as I can manage it. I'll be swapping it when I can, not as soon as I can. I sure miss having a shop with a lift
Quaife is still on track to manufacture the first batch of ATB units for our Jaguar F-Types in January 2024.
So far we have reserved 7 helical ATB units... but there are 3 more in the initial batch that we can take advantage of.
Two additional forum members have asked about getting in on the helical ATB build. (Joey T. and Jim L.)
In the mean time I have put together a draft of the rear differential swap process, which can be carried out by a well equipped mechanic / garage.
Best, Herman
Quaife is still on track to manufacture the first batch of ATB units for our Jaguar F-Types in January 2024.
So far we have reserved 7 helical ATB units... but there are 3 more in the initial batch that we can take advantage of.
Two additional forum members have asked about getting in on the helical ATB build. (Joey T. and Jim L.)
In the mean time I have put together a draft of the rear differential swap process, which can be carried out by a well equipped mechanic / garage.
Best, Herman
Hey Herman,
Sorry if I was pestering you with all the emails. I hadn't received any reply from you after my initial email so didn't realize that you had read my email.
Looking forward to more updates!
Saw your video regarding the diff swap procedure. Having to drop the subframe is quite a big pain point. Not something iId want to do on my back either.
Wonder if it would be possible to fit the diff unit into the housing without removing the housing from the vehicle? (Like is commonly done on ford rear ends)
I noticed that the jag unit seems to have unbolt the diff cover from the side so not sure if there would be clearance for this... Maybe with the axle on that side fully removed?
@JoeyTheAsian
No problem, don't worry about your multiple e-mails.
Let's take this conversation into the Private Messages part of the Jaguar Forums, as that may work better.
I have room for one or two more in the initial Quaife ATB build.
Try this link to your "Private Messages" portion of the Jag Forums. https://www.jaguarforums.com/forum/p...php?folderid=0
=========== Update:
It appears that you have turned off your Private Message option on the forums.
Error message: "JoeyTheAsian has chosen not to receive private messages or may not be allowed to receive private messages."
Best,
Herman
Last edited by HermanWiegman; 01-11-2024 at 08:29 AM.
*EDIT It looks like my PM restriction has been lifted and I've gone ahead and sent you a message on the forum Herman.
Yes it appears my account is too recent to be able to receive PM's. I checked my spam folder and couldnt find your emails either Herman. Could you shoot me another email?
-Joey
Last edited by JoeyTheAsian; 01-12-2024 at 10:59 AM.
Update: Jan 29, 2024
I visited Quaife this past week, and toured their Vestry Road facility in SevenOaks Kent.
The first gears for the ATB units are being cut, and completion should be in the next few weeks.
I have sent out a separate e-mail to the 8 Forum members who are on this first build. (look for the OncaEngineering e-mail)
I am also refining the rear differential rebuild process which will address the known issues with Jaguar V6 rear diffs:
a) pinion oil leak - leak down test on donor units to determine if pinion seal needs replacement
b) side cover oil leak - UltraGrey RTV sealant bead size/pattern and squeeze out tests
c) axle oil seal leaks - seal alignment and axle insertion process
d) diff oil life - use of the helical ATB to reduce oil temperature
Qauife steering gear components Quaife sequential gear box gears Quaife ATB units for a Honda application
@diablo2112 Understood.. the V8 e-diff has some challenges.
Let me finish the rebuild process on the V6 (and I4) rear diffs first.
I think there may be a few options for the V8 owners with rear differential unit issues:
pinion yoke seal issues, offer a rebuild kit with tool rental (can be done in car)
cover oil leak, offer a rebuilt diff unit with core unit/deposit upon return (may need reshim to get preload correct after new RTV seal)
electronic control unit issues.. offer a new control box, or convert the F-Type V8 to a V6 rear diff unit with 2.56 gear ratio?? (tough job)
slipping disks... offer a rebuild service with new friction disks... with core unit / deposit upon return.
In the mean time, change your diff oil with Castrol BOT 720 frequently.
Personally, I'd prefer a mechanical LSD from the V6 at the right ratio (2.56) and bypass the motor/electronics. The eDiffs seem to have quite a bit of premature wear. Not sure if replacement with an mechanical LSD will throw codes or cause issues with the DSC in the Rs. May require a level of coding that could be tricky for a home mechanic DIYer.
@diablo2112
I am seeing many failures of the friction material in Jaguar V6S friction LSD's. See YouTube @OncaEngineering
I am developing a rebuild solution with Racing Diffs to get an improved clutch discs set for that application.
The drivetrain control module in the V8's may not like having an unplugged eDiff control box.. but the "analog" LSD (either Jaguar friction, or Quaife helical) should still work to give reasonable rear traction.
Either way... these are options to explore in about 6 month's time.
Last edited by HermanWiegman; 01-29-2024 at 03:42 PM.
I slighlty misspoke. I should have said, I'd prefer a reliable mechanical LSD. Your helical unit seems the way to go compared to the clutch-stack which is OEM. Keep up the good work.
07-31-2023, 09:44 PM
