Quaife differential

[Bearman]

Hello, Just wondering if anyone has had any experience with a Quaife diferential in the front diff of a defender. I am curious to know if there is any steering effect and whether they are of any benefit or not in terms of traction.Any help appreciated......Brian

[rick130]

No first hand experience but I believe they are based on the first generation Torsen.
The Quaiffe ATB diff is used OE in a lot of the Ford RS hot hatches in England, so it should be pretty benign in nature.

The downside of any torque-biasing diff is they need a modicum of friction on the wheel with the least traction to bias, so if you lift a wheel that side will spin and you lose drive to the grounded wheel.
Some left foot brake to bias the diff when lifting a wheel.

[spudboy]

The Quaife-syle diff that gets a lot of mention here is the TrueTrac. They are available in Australia from Locked Drive Systems.

Recommended for the front diff instead of a full locker, as much kinder to the steering response.

Not sure of the exact cost, but I gather around $600 or $700ish, but someone who has bought one will surely correct me if I am miles out.

[streaky]

I had the Quaife Torque Biased Diffs in the front and rear of my 130 and didn't notice any ill effects on the road.
They were installed when I bought the vehicle though so I couldn't give you a 'before and after' report.

S.

[Bush65]

I have tru tracs (similar to quaife) front and rear in my disco.

Tyre pressures need to be reasonably close or they tend to pull to the side with low pressure.

Otherwise no problems/issues with steering/handling associated with tru trac.

I have 3" lift, and no castor correction - it could be that the tru trac in the front helps to stop wandering.

[Slunnie]

I think in real terms, the biggest difference between the TT and the Quaife is the biasing ratio which IIRC was 1:3 in the TT and 1:4 in the Quaife, so the quaife I thought was a more positive drive. Aside from that they do the same thing

[PhilipA]

I had one in a RRC and found that there was a slight resistance to initial turning . EG going into a curve you would slightly turn the wheel, and nothing nothing then turn. Also as stated botrh tyres had to be the same diameter and/or pressure or it would pull to the smaller tyre.

Otherwise no ill effects. I removed mine as it was badly set up/noisy and had a pinion bearing leak. I might yet replace it if I can be stuffed to have it rebuilt and fit the damn heavy thing.
Regards Philip A

[ashtrans]

Hi as stated the Quaife and True Trac work on the same principle,(totally different from the Torsen) the Quaife is better engineered, has six sets of cross gears, the True Trac has only 3, the quaife is made from better materials and will last longer. As for performance the two are very similar with Quaife having the edge but the Quaife will do it for longer. Down side is the Quaife costs a little more.
Regards Ian Ashcroft

[Zute]

But in a dollar per performance comparison, are these diff Worth the money over a air locker or such ?

[Bush65]

But in a dollar per performance comparison, are these diff Worth the money over a air locker or such ?
No, unless your vehicle is fitted with traction control - then these types of diffs will work extremely well.

I fitted the tru tracs in my disco because I needed something stronger, better traction on boat ramps etc. and it was not intended for hard wheeling (my other 2 4wd's are double locked), also I was interested in finding out how they performed.

[justinc]

IMHO the fitment of twin truetracs in a Automatic vehicle is far better, as using the brake gently to aid traction turns these diffs into almost lockers, they are that positive:) It is very difficult to do this in a manual one for obvious reasons. This is an observation based on driving 2 twin TT equiped D1's, 1 auto and 1 manual through the same terrain.

JC

[rick130]

My bad, the T2 Torsen is similar to the Quaife ATB and Tru Trac which all use parallel axis planetary worm gears.
The Torsen T1 (the original design) is a fair bit different with the worms going across the axis.

Quaife ATB

http://www.import-racer.com/2/quaife-cut.jpg
https://www.aulro.com/afvb/images/imported/2009/08/844.jpg


Torsen T2

http://www.torsen.com/images/T2b.jpg
http://www.torsen.com/images/T2color2.jpg
T-2 (http://www.torsen.com/products/T-2.htm)


Detroit Tru Trac

https://www.aulro.com/afvb/images/imported/2009/08/845.jpg


T1 Torsen

http://www2.zhome.com:81/ZCMnL/tech/Torsen/Figure1.gif


Torsen (http://www2.zhome.com:81/ZCMnL/tech/Torsen/Torsen.htm)White Paper

http://www2.zhome.com:81/ZCMnL/tech/Torsen/Torsen.htm

[ashtrans]

Hi Rick130 excellent posting good tech, the Quiife/TT used with left foot braking is good but if you have traction control they are fantastic. as the Traction control applies just enough brake to engage the ATB. Regards Ian Ashcroft

[rick130]

thanks Ian (or is it Dave this time ?)
Yep, I don't know if you remember, but a couple of the boys that founded the Outerlimits forum found how well a torque biasing diff can work when they made their own pneumatic TC system and used it on a comp buggy with Tru Tracs.

re the original Torsen, now termed the T1 (and FWIW was designed by a Mr Gleasman and a durable, workable model only able to be finally produced by Gleason, everyone confused yet ?? :D)
I'd read in the past in a tech book, and the white paper I linked to confirms better than 6:1 bias ratios are achievable which would indicate it's a better proposition for the rear axle in an off roader than the simpler to make parallel axis models

From what i've read, the T2/ATB/Tru Trac are a better proposition in a steering axle thanks to the milder bias ratios, and whoever is now the owner of the Torsen production often use a different bias ratio (and i suspect Quaife do too, but they don't divulge) in a front steering axle to rear in AWD models.

[ashtrans]

Hi Rick Dave is on Holiday so I am temp reinstated, we tested a number of T1 Torsen which were sent to Land Rover for evaluation, they just did'nt survive, the little gears at the side sheared off in very short time and the cases split, this was off road comp safari racing. e.g. failed after one circuit of a comp safari. I have never seen a T2 for the Rover but believe they are used on other 4X4, as you note the T2 is identical to the others except for axial gears, possibly to get round some design protection. Regards Ian

[rick130]

Hi Ian,
that's exactly what I read happened on circuit race cars years ago too.
Too many small bits taking high torque loads coupled with cases not strong enough for race use.

Apparently most of the gear problems were overcome, what I read it took a company with Gleason's metallurgical resources to do it, but one of the other downsides with race use was the high moment of rotational inertia and the friction (heat) involved in it's operation.
There were some aftermarket steel cased units made in the US that overcame Gleasons ductile iron case problems too, the iron cased versions were a grenade waiting to happen apparently.

Have you ever seen inside a Weisman locker ?
Would it have any application as an off roader diff ?
While a torque biasing diff they lock 100% under torque, open in coast.
Were very popular in F5000, F1, F2, Can Am, etc in the seventies/eighties.
Does anyone make them anymore ?

[JDNSW]

May be of interest, I have in front of me a description of a Torsen type differential (unfortunately with a not very good picture) named a M & S or Brown-Lipe-Chapman. The book it is in was copyrighted 1909-1926. It seems that the basic design goes back a lot further than anyone is prepared to acknowledge. Probably either not successful, or, more likely, too expensive to make; certainly it would not be very strong given the metallurgy available then, but powers available were nowhere near what became possible after WW2.

John

[rick130]

I'm not surprised John.
The Dual Drive differential that is now known as the Torsen was patented by Vernon Gleasman in 1958.
I remember seeing the ads for the Dual Drive differential in the US magazines 'Four Wheeler' and 'Off Road' that Dad bought when I was a little tacker in the early seventies.

Interestingly, one of my race car tech references states "Gleason (http://www.gleason.com/) wrote the book on gears in the 1920's, all we've learned since then is metallurgy"

[JDNSW]

I'm not surprised John.
The Dual Drive differential that is now known as the Torsen was patented by Vernon Gleasman in 1958.
I remember seeing the ads for the Dual Drive differential in the US magazines 'Four Wheeler' and 'Off Road' that Dad bought when I was a little tacker in the early seventies.

Interestingly, one of my race car tech references states "Gleason (http://www.gleason.com/) wrote the book on gears in the 1920's, all we've learned since then is metallurgy"

There are similar "surprises" when you talk about just about any "new" ideas in motoring, or probably most other fields for that matter. The lag between when an idea is first thought of, or even first tried, and when it becomes accepted or common, can be many decades. This can be for a wide variety of reasons, but probably most commonly because there is no real need for it when first thought of.

John

John