Frequently Asked Questions - Differentials, CW&Ps & Drive Train

Whenever you ‘upgrade’ you move ‘the weak spot’. On a standard axle, front or rear, the weak spot is either your half shafts or the 2 pin diff. So changing the diff for say an 'Ashlocker' means the 'weak spot' is moved - and is now absolutely definitely the shafts. And the 'locker' is going to put far more strain on the shafts than your open diff ever did.

Our recommendation is to do 1 x axle at a time, and do it properly. If you just upgrade both axles with say 'Lockers', and nothing else, you risk the standard shafts exploding under the additional strain being placed on them - potentially then taking out and damaging or even destroying your expensive new Locker.

So, the answer is : back axle 1st, front axle second.

Your rear axle works harder, ie 'foot down' going hard up a hill = all the weight on the rear axle & its components, whilst front axles are normally scrabbling for grip. The front axle however is normally not worked hard when all the weight is on it – ie going down a hugely steep hill may mean the weight is over the front axle, but the power is often not on at all whilst you 'squeak n squeal' a bit …..

The answer is upgrade the rear axle centre AND at the same time fit upgraded 'Half Shafts'. We stock Ashcroft HD Shafts – and 'Drive Flanges' too. Standard 'Drive Flanges' are prone to spline wear and also allowing water in, er - which is not good !. Lastly, add a X-Eng 'Magnetic Drain Plug' (see Off Road Products)

Once this is complete save for the front axle. A rear 'Locker' transforms your off road abilities. A second 'Locker' is not 'twice as good'. Better yes, but not twice as good. Again – centre change ie 'Locker' AND shafts. Unfortunately this may also mean a CV upgrade too, dependant on axle type. KAM & Ashcroft both offer superb solutions, both have pros and cons, and approach the solution quite differently - both are seriously strong. There are such a range of front axles and internal variances that you may find a call to us can save you a awful lot of time and research. Front axles are unfortunately much more expensive to upgrade properly than a rear.

Tricky to explain quickly but here goes

In a rear diff the CW&P is cut at an angle, and the drive from the pinion is transferred to the strongest side of the teeth called the 'Drive' side. On a front diff the drive is 'reversed', so the drive is enaged on the weaker side of the tooth, called the 'Coast' side . This means that the rear diff is stronger in action than the front.

Reversing the cut angle on a front diff means it is then driving on the stonger side. This is why reverse cut gears are available. However to complicate matters it means your rear diff then can’t really be used in the rear axle as its weaker, and as in the previous question rear axles are worked harder, and take more abuse than fronts.

Secondly front axles tend to only be heavily over loaded when you are heavily nose down and stuck badly, you then select reverse gear and 'booting it' – in 'reverse' the reverse cut gear is now on the weaker 'Coast' side. As such we recommend for 'Comp Safari Racers' yes 'Reverse Cut CW&Ps', but for general 'Off Road' use, 'Trials and 'Challenge Events' 2 x standard cut gear sets is best, but it’s a area open to much debate – these are our own views !.

But, add a 'Pegged Casing' (See Video) into either of the above scenarios – and you add MASSIVE strength

Simples – 10 Spline assembles & shafts etc are far weaker than 24 (see video). We will repair and upgrade customers 10 spline diffs - ie early ARBs, but any 10 spline unit is weaker than equivelent 24 spline assembles. Additionally, there are very few 'HD' 10 spline shafts upgrades available, those that are (GKN) are frighteningly expensive and still weaker than the same KAM or Ashcroft 24 spline HD units.

Simple when you know how - and to know how click on the picture to the left < -----

Also - very simple when you know how - and to know how click on the picture to the left < -----

Yes ......and more likely ...Ermmm..........No.

37s frankly are too big for a Land Rover axle set up - however exotic a build spec they might be.
35s are either 'On' or even 'Over' the reliabily limit, ...the smaller the tyre the less weight, and its weight that can be the killer

We recomend any tyre at 31 inches + is time to consider having them 'Pegged', but even Pegged 35s can do lots of carnage if you go too mad, 37s can do the same when you think you are going easy !. Whilst we do have customers who have this set up, and do heavy competitions, the 'reliabily factor' really is not there.

To stand ANY chance of the entire Axle(s) not blowing themselves to expensive bits you will need to invest heavily. Not just HD Diffs, you'll need HD half Shafts, HD Drive Flanges, HD CVs, Pegged Differentials and HD 4.75 CWPs and our Tablock Upgrade if an Ashlocker ....the bills to get to this level are BIG.

For more reliability if you want to run 37s - you are into 'Y61' territory, and these axles bring along their own issues - the big one is mainly even bigger bills !.

Having said all this we do have customers who understand this, have mechanical sympathy, and drive accordingly - even so ...things in a split second can still go very very wrong followed by a huge BANG ....and often both 'expensive' bangs and 'spectucular' bangs !.

In simple terms our advice is don't. Wwithout spending a LOT of £s you stand little chance of the axles holding together, and even with big £s invested, any 'Hold my beer and watch this....' moments will end in tears.

YOU HAVE BEEN WARNED lol

One of several things. The most common 2 are too much ‘lift’ casing a too 'acute' a propshaft angle, sometimes even 'locking' the prop flanges on near or full travel – you need a high angle prophaft. Second is worn or knackered UJs in the propshaft (you have to have the prop disconnected to properly check UJs). Either will wreck a pinion bearing in double quick time. Also a stuck propshaft 'slider' will quickly cause this type of damage.

You can’t over grease a UJ, and good practise is to regreasae EVERY time after going off road or deep water.

Then write them all down, get a list of what exactly your unsure or concerned about and either email us on megasquirt.v8@gmail.com or ring us for a chat. We will do what we can to explain what your uncomfortable about. We would far rather you talk to us and then decide to buy, or even not buy, than spend money on something your unsure of, or get the wrong diif, ratios or unit. If you look at our testamonials and feedback from our customers you will see we try hard to have happy customers. We don't advertise in LR or Magazines etc, we trade on reputation and recomendation, and we love to chat with Land Rover owner and talk diffs n drivetrains (yes we are a bit sad - we know)

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