LSD or Quaife

[garryc]

Has anyone any experience of fitting an LSD or Quaife type differential to a S3?

Looking for options to improve rear traction on my 82 Lightweight.

Thank you

[Hybrid_From_Hell]

 

A quaife is an ATB "Automatic Torque biasing" differential, vs a Traditional LSD "Limited Slip Diferential"

Basically they do the same thing

 

ATB via Gears, and a LSD Via Plates.

And a Tru Trac is also an ATB, same as Ashcrofts ATB

Bit like a Samsung vs an iphone  - you can do the same with both - just differently .........

 

ATBs are set at the factory for the "grip", and TruTracs can be build for Rear or Fronts (Rears give more grip) Quaifes same front and rear

However, series 3 being 10 spline your options are limited, 

You can buy new Quaife and TruTrac, - both are BIG money  I am unaware of any plated LSD 10- spline available new.

Plated LSDs also wear quite quickly on road use and need resetting, ATBs don't have this issue, and LSDs with plates need special oils, ATBs EP90

Plated LSDs like the KAM units can be "Tuned" for more / less grip, but again 10 spline now very rare, so one option would be to go 24 spline and add Ashcroft ATB + 24 spline HD series shafts, then you have more choice.

ATBs or LSD set up correctly will make a significant difference to handling both on and off road, also I have argued with many people that a LSD/ATB is actually softer of half shafts as the open diff lets you spin wheels etc, meaning 100% of all power is going to just the one rear shaft, or, in the case of your S3 all power to just 1 poor half shaft, as opposed to ATB / LSD balancing the output

But I have never heard of anyone NOT liking then, as opposed to say a Detriot Autolocker in rears, those are marmite units !!!!!!!!!!!!!  

Lastly be careful of second-hand units, often these are old, may have been mistreated and parts can be near of impossible to get.....

I think I may have a 10 spline Tru Trac on webshop, need to double check as been offline for MRI scans and Physio on elbow having managed to break elbow in 2 places at Christmas - let me know if intersted !

Nige

[garryc]

Nige,

That sounds painful. Sorry to hear that

Let me know if you've got it and how much you want for it.

Thanks

[Snagger]

ATB or LSD?  Definitely ATB - not just for the maintenance reasons Nige mentioned, but also because an LSD starts out locked and slips when there is enough differential wind up, so will force skids on wintry roads, while the ATB is the opposite, starting open and cross feeding torque when a wheel looses grip, so safer on the road.

I have built up a Rover diff for my 109.  As Nige said, you’d need 24 spline shafts, but otherwise will fit.  Ashcroft sell a spacer ring so that you can use 4.71 gears and bearing sleeves so you can fit it in a Series diff casing.  This is my build thread (ignore the stuff about the 4.1 gear sets).

Quaife and Ashcroft ATBs have the same number of scroll gears, double those of the Eaton Trutrac, but Quaife are twice the price of Ashcroft, so while Eaton and Quaife do 10 spline options, the cheaper Ashcroft will allow the money saved to go on stronger 24 spline shafts.

[92a]

I recently bought a new 10 spline  Eaton Truetrac from Island 4x4 and got Nige at Xcess4x4 to build it up for me and I am very happy with it , I had a Detroit locker before and it was an awful thing , once it had broken the short half shaft it was actually better, I part exchanged it when I got my Truetrac ,