The diff in my XJR is dead. It turns out this is a common issue as the 14HU diff is weaker than its forebears while the power and torque it has to handle is greater. So broken teeth rattling around is the issue. I therefore want to swap the internals if possible. I have read that DANA 44 internals will fit straight away. But will the pinion from DANA take the flange for the Jurid / Hardy coupling? If not the prop shaft will have to rebuilt. And so on....? And what are the actual DANA part numbers?

Further I want to add LSD, will Quaife still fit DANA (pinion and) ring gear? It should, but then again...... Any alternatives to Quaife? Torsen?

 

The one member I know that can answer that and he is Count Iblis. He has done the Dana retro. You may wish to contact him about pricing.

 

the way he did it is very expensive. much cheaper and easier ways to do it

 

Is there an LSD that will fit 15HU factory pinion and ring gear? I am confused about which period Jaguar did not supply LSD. The word is that in order not to outdo Aston Martin DB7 Jaguar were not allowed to fit LSD to the XK8 in any variety. And therefore XJR was not allowed either.

 

Yeah, I know, but he is the only one I know that's done it.
As for myself, I'd like to get a diff out of a 2012 and newer Mustang. They come out of the factory able to handle over 500hp.

 

all xjr6, some xj40s and late xjs v12. they need new clutch packs though or you will have a one tire fire

or you can drill out a new 19 spline d44 limited slip carrier holes to 10mm and bolt the 15hu ring gear to it. either the auburn cone or the speedmaster torsen type.

https://www.speedmaster79.com/DANA-44-19-Spline-3.73-and-Down-TorqueWorm-LSD-Limited-Slip-Differential

 

What breaks in HU15 ? Diffrential small gears? If so by replacig them with quaife locker what is mafde for xk8 should do the trick ?
Quaife

Didnt't xk8 use same hu15 diff as xj8 ?

 

I guess you mean 14HU. It's just 8" and was never enough strong for supercharged. The angle between pinion and crown wheel is wrong. Too much load for a few teeth.
Older, a step stronger 15HU is 8.5". Shot peening ans some cryo treatments of stock internals makes them more cacable to take that load.

I have broken both, 14HUwith Quiafe ( two broken pinion teeth ) and now stock 15HU with L ( not yet opened , but sounds like same problem ).

 

Having looked at the specs for xj40 and x300 it looks like none of the 15HU diffs had 3.06 ratio? Is that correct? That means somehow fooling the gearbox control unit to avoid limp mode (the sequence done at every journey start referred to in another thread is not for me, I want something simpler). I have searced for the ford electronics box for fool fooling the TCM in the ford performance catalogue but found nothing.

 

@Chirpy already made a canbus signal modifier and somebody has already used it for their swap. you can have any ratio you want

not needing to match ratios means use you can use a 15HU ring and pinion, save money and have better gearing anyways

 

Oh yes. 14HU.. Mornings.. Okay pinion gear goes. Then locker isn't the fix.