Thread: Land Rover Diffs

H260 (260mm crown wheel) are a large diff, with 37 (not 35) spline axles. I thought they were full floaters, but will accept some may be semi-flt.

I've not had much to do with the H260, because of it's size. Unless using very large tyres, the H233, is a more suitable size for a rover IMHO. By my best measurements, compared to a rover flat bottom diff housing, the H233 only looses 14 mm ground clearance, but a disadvantage is the rear is centred so further from the tyre which when put on a rise lifts the diff closer to it, and because it doesn't follow the groove of the front diff, results in more drag in some cases.

In my experience, Nissan uses more, finer splines on their axles, so larger root diameter, and slight increase in fatigue strength.

Torsional strength of shafts is related to diameter cubed, which is why strength increases significantly with small increases in diameter - double dia gives 8 times strength. Our axles fail in fatigue which can be much lower than static strength and is greatly influenced by stress raisers (static strength is not).

The other equally, or possibly more important issue is shock/impact loading, which is greatly influenced by the ability to transform impact energy into strain energy. Being able to absorb the impact energy also lessens loads on cv's and diffs. For this resilience and notch sensitivity is important (hi-tough and 300M have exceptionaly good impact energy properties). Obtaining high resilence is all about obtaining near equal stress in the largest volume of the material, which relates to strain energy - definitely need waisted axles for this.

In my experience with tru-tracs, they will pull to one side unless the tyres are inflated for near equal diameter. Then they track nicely, even with big lift that has a detrimental effect on castor. In this case steering is light, I could imagain steering might be heavier at stock castor.

Originally Posted by PhilipA

Apparently not with the Quaife as I asked them before I put it in the front ( reverse rotation) and they said it will work fine.

My question
I have a Quaife differential fitted to a rear differential centre for aRange Rover Classic which I plan to install in my FRONT axle. Can youpease advise whether it will perform properly in this role , as thedifferential will be turning backwards compared to rear axle operation.Regards Philip Armbruster
His reply
These will work perfectly well reversed Phillip.Len Kind regardsLen UnwinQuaife Technical Sales

Dosent sound right to me
I got my Advise from Great Basin Rovers in Utah (BTW they have a $60 shipping deal) The Front & Rear truetracs ARE different, and have different part numbers. I def would not use a rear in the front, Since Qualfe is the same basic Torsen design there must be some misinformation about.

read this
Detroit Truetrac Limited Slip diff - LR4x4 - The Land Rover Forum

and this
http://www.alljeep.com/tech/install/..._true_trac.htm

Hey Phillip,
More info on flipping your Truetrac from rear to front.
I can't see what makes the Qualfe different

Also the instructions that come with the diff says do not dismantle, The bearing seats and crown wheel flange are finish machined after assembly and if carrier is opened may result in runout.

Flipping Truetrac Gears

I'm fairly sure Truetracs have different preload for front versus rear, giving a different bias. Ashcroft ATBs are the same preload/bias whether front or rear, despite being the same design albeit with more worm gears as the Truetrac. I think the ATB in my County is great and am considering putting my spare in my Series' front. Even with armstrong steering I don't think the difference will be too noticeable on the steering effort needed.

Originally Posted by Dougal

Nope. But ashcroft ATB's (torsen) are on the shopping list.

Torsens are everywhere these days. Factory fitted to the centre diffs of everything from rangies to audis.

So how do you know the effects on how they drive?

Originally Posted by Bush65

H260 (260mm crown wheel) are a large diff, with 37 (not 35) spline axles. I thought they were full floaters, but will accept some may be semi-flt.
.
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37! Well it's about 5 years since I've had one apart, that was a gq leaf, with semi float, had to do a wheel bearing, gu leafies are full float, I think it's 4.5 wagon and some zd30 that have the h260 semi float coiler, there is no real pattern

Even Nissan nutters don't use them as the strength increase over a h233 is negligible, getting headsets for ratio changes are difficult and decrease in clearance

To those talking about flipping Truetracs, that is why I wrote the email to Quaife, as a result of seeing posts about flipping Truetracs, as I was about to rebuild the Quaife.

I think the technical manager of Quaife would know his stuff. maybe more so than posters on Forums.
There are some differences as detailed in this , particularly the post by Dave Ashcroft.


Quaife diffs - LR4x4 - The Land Rover Forum



I must say that in difficult country, I cannot really feel any effect from the Quaife other than when allied to the Maxi drive I seem to be able to drive country that others cannot
EG climbing out of Canal or Mistake creek on the Northern OTL there is a chicken track and a very difficult climb out straight up about 200metres of chalky wet clay. I missed the chicken track as it is out of sight to the left and noone in front of me. I was able to climb the hard track towing my Campomatic , with one stop where the trailer spare dug in, which I was able to reverse out of.
This is the site of a "last page pic" in one of the Motoring mags where a cruiser got stuck by itself on the initial jump out of the creek.
Some people I had met earlier in a Patrol also found the Northern exit of another creek really hard, (Cannibal?) where I hadn't spun a wheel.

So it seems to work along with the maxi, especially since I removed my stab bars , so had good front articulation on the trip.

Regards Philip A

its ok guys, im on your side......I have never said the Rover type is better ANYWHERE. How ever, I will stand by my statements and questions.

Rovercare, you say real life not theroy is important....sure, but all your real life started in someones head or the drawing board as theroy, probably a Mech. Eng.....Now you say spline dont matter, I say BS. Is a 32 spline rove axle only a touch behind a 35 spline DANA or 37 spline Nissan??? You say youve broken stuff in real life, thats great, I dont have the luxury as my LR IS my DD and I need it Monday morning, rain hail or shine ready to tow 1.8t. I have been lucky with my driveline, but then again i built it above my requirements. Full MD front and rear on 32-34s.

Your H260 is actually 37 spline and while found in SOME coil sprung Nissans is much more prevelant in the leaf sprung rigs. These dont show the numbers of the H233 coiler alxe that has been hammered in comp and have broken a thing or 2. I have read (yes theroy, but someones real life) that the axles are the weak link and that Nissan axles have been described as "brittle" (this coming from a comp truck driver/builder who also is a Mech. Eng.)

All I did was question the statement of Slunnie, not having a go, but not wanting to believe the hype....after all its real life we want right

Ben, I have been banging on about the sixty9 here since I first read about it. I have been giving what little encouragement I can, to JRAT to keep pushing it as I think it is a great option for the LR. I have also been in touch with Dan from Ruffstuff specialties trying to get info on their HD Rover front housing for the Isuzu guys here. Yep Fabbed housing with a GOOD hypoid is the go IMO.

Slunnie, I wasnt having a dig mate, and with Bush65 tech, it may well be that the Nissan axle is not twice the cross section BUT actually twice the strength. But some of the variables are material and design. I have not seen a Nissan axle so cant comment on waisting smooth transitions etc.

Sounds like the go would be a housing by Ruffstuff, H233 center with 35 spline axles, modded Rover hubs and stub axles. Or just the sixty9 as you could make it into a Sals or D60, High or Low and have a fabbed housing with better clearance than a stock Sals/D60

btw H in the Nissan axle code is for Hitachi, the makers