Thread: Quaife LSD centre diff

The guy's at Ashcroft transmissions reckon they're great.
A gear type LSD is effectively a torque sensing diff like a Viscous Coupling.
So, I know they work and I know they fit.
So back to my original question....Is anyone running one here in Oz because it's all very well to sell them but I want to know from an actual user what they're like?

Originally Posted by wrinklearthur

Ref; QDF30KR - Quaife Engineering



It reads like it is a arrangement like a True trac has.

Exploded View - Inside the Eaton TrueTrac Differential - YouTube

.

Yes, and if you lift a wheel with a truetrac it reverts to completely open, like a standard diff. They are torque biasing. Zero torque going to one side = zero torque going to the other.

Originally Posted by BigJon

Yes, and if you lift a wheel with a truetrac it reverts to completely open, like a standard diff. They are torque biasing. Zero torque going to one side = zero torque going to the other.

So that is why I have a ARB Air locker in the Salisbury diff of my Defender.

Most times you haven't got time, or enough feet, to keep a little pressure on the foot brake to keep the True trac engaged.

.

Originally Posted by wrinklearthur

So that is why I have a ARB Air locker in the Salisbury diff of my Defender.

Most times you haven't got time, or enough feet, to keep a little pressure on the foot brake to keep the True trac engaged..

Ah, the advantage of a slush-box and habitual left-foot braking...



Would'nt a diff locker at both ends, fed from an unlocked centre-diff give a pretty good all-round performance? - with the centre-lock in reserve for the worst of the worst...

Originally Posted by BigJon

Expand and discuss.

This should be good.

OK Jon, I'll bite seeing as I made the sweeping statement in the first place.

I actually checked Quaife's website before posting, under gearbox and differential and found no listing. Obviously looked in the wrong place.

I'm of the view that the terrain I'm driving in determines whether the centre diff should be locked or not as opposed to the manner of driving. Particularly with issues of a (centre) LSD unlocking/locking as drive changes to front/rear open diffs. But if as FIXR7 says they operate more like a viscous coupling I could be talked around.

I had visions of driving down a long windy bitumen road with a centre LSD operating and slowly winding the transmission up like a clock spring.

Deano

PS. I've got a feeling that LR played with LSD centre diffs in early RRC's but after chewing them to bits gave it away as a bad idea.

Originally Posted by DeanoH

I had visions of driving down a long windy bitumen road with a centre LSD operating and slowly winding the transmission up like a clock spring.

Deano

PS. I've got a feeling that LR played with LSD centre diffs in early RRC's but after chewing them to bits gave it away as a bad idea.

The tip is in the name. Limited slip. They do allow some slip, hence no wind up.

You are correct about very early build RRCs having a limited slip centre diff, but as you say they were too fragile and were dropped from production.

according to this lotsa OEM's use the Torsen type centre diff....
They're even suggesting the L322 type Rangie uses one?
[ame="http://en.wikipedia.org/wiki/Torsen"]Torsen - Wikipedia, the free encyclopedia[/ame]

Originally Posted by BigJon

Yes, and if you lift a wheel with a truetrac it reverts to completely open, like a standard diff. They are torque biasing. Zero torque going to one side = zero torque going to the other.

Excellent question Jon. I always assumed that the locking mechanism remained so you would have torque biasing operation when unlocked and still locked when needed.
But I haven't found anything to back up this assumption. Can anyone confirm/deny if the LT230 locking remains?

Originally Posted by DeanoH

OK Jon, I'll bite seeing as I made the sweeping statement in the first place.

I actually checked Quaife's website before posting, under gearbox and differential and found no listing. Obviously looked in the wrong place.

I'm of the view that the terrain I'm driving in determines whether the centre diff should be locked or not as opposed to the manner of driving. Particularly with issues of a (centre) LSD unlocking/locking as drive changes to front/rear open diffs. But if as FIXR7 says they operate more like a viscous coupling I could be talked around.

I had visions of driving down a long windy bitumen road with a centre LSD operating and slowly winding the transmission up like a clock spring.

Deano

PS. I've got a feeling that LR played with LSD centre diffs in early RRC's but after chewing them to bits gave it away as a bad idea.

These don't lock/unlock. They are better viewed as a very strong but inefficient open diff. Where they aren't very good at letting the outputs spin at very different rpm's.

Originally Posted by FIXR7

according to this lotsa OEM's use the Torsen type centre diff....
They're even suggesting the L322 type Rangie uses one?
Torsen - Wikipedia, the free encyclopedia

Found in a huge range of awd vehicles, including audi Q7/vw tourag/porsche cayenne and many others with a north/south driveline.