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Front and Rear Diff Locks

If you have introduced items like larger tyres, diff locks or even more power it is important to increase the strength of the drive line to decrease the risk of component failure but more importantly increase the safety of the vehicle for its passengers. 

Locking Differentials

If you a serious Off Roader then your best option is for a Locking Differential to give you optimum performance.

The locking differential fits into the centre of your standard differential and adds an electric, pneumatic or hydraulic mechanism to lock the two output pinions together. The Locker when activated will make both wheels will spin at the same speed, so if one wheel is off the ground the other wheel won't know or care and both wheels will continue to turn at the same speed as if nothing had changed. When unlocker, for example, on the road, the differential behaves as a normal open differential giving equal torque to each wheel, whilst allowing the differential action.

There are two types of Locking Differential, driver operated and automatic.

We are able to offer the Ashcroft Locker . These are the driver operated lockers and are activated by a switch in the cab and will also require an on board air supply. The benefit of this type of locker is that it gives you 100% lock up when required and that the driver has total control.

The automatic Locking differential (which should really be called an automatic unlocking differential) is locked whilst both wheels are turning at the same speed, e.g straight ahead on the road. The locking/unlocking occurs when cornering and the outer wheel travels faster than the inner wheel, this increase in speed causes an internal mechanism to release drive to that wheel. At no time can a wheel be driven faster than the differential centre, the only possibility is for the wheel to free wheel faster than the differential centre. The advantage is there is no external operating source required and does not rely on driver input. The disadvantage of this it is not under driver control, on road this can cause some peculiar handling characteristics as wheels alternatively lock and unlock when driving round bends or corners. This locking and un-locking in some designs, e.g the Eaton locker, of automatic locking differentials can be the cause of noise/backlash

Depending on what type of off roading you do you may also want to consider a limited slip differential usually find these are best suited to the faster rally raid events and also the customer that does less severe off roading and doesn't really require a full 100% locking.


A: Rear diff lock on standard diff ratios


All Land Rovers will benefit from a rear Diff Lock.

Note: If the diff has done more than 200,000Km it is recommended the crown wheel and pinion should be replaced as the rear diff will now be exposed to forces more than 4 times greater than the rear diff has experienced before and a 200,000Km + item is already weakening. The rear suspension ball joint rear should also be upgrades due to the extra forces applied.

B: Rear diff lock changing diff ratios


All Land Rovers will benefit from a rear Diff Lock. Changing the ratios is normally used to correct the overall ratio change from fitting larger tyres. (Use Ashcroft Rear Diff Lock and a crown wheel and pinion ratio to suit your needs.)

Note: If you choose to change ratios you MUST replace the front crown wheel and pinion to match the ratios. The rear suspension ball joint rear should also be upgraded with a heavy duty unit due to the extra forces applied.

C: Front diff locks and upgrades.


If you chose B: above and are changing diff ratios the front crown wheel must be changed. The front diff can be rebuilt in standard form, upgraded centre with the option of a diff lock or an LSD latter or set-up exactly what you desire from the start. (For upgrades and lockers use Ashcroft diff locks)

D: Switchgear for diff lockers

The beauty of the Ashcroft diff lock system is the diff lock is activated by an ARB compressor and pugs straight into the ARB loom.  This also allows the use of electronic switches, either Ashcroft / ARB supplied switches, the addition of the Carling range of switches or the manipulation of factory Land Rover switches to activate the diff lock.  In most vehicles we opt to manipulate the Land rover switches in our workshop as it avoids cutting extra holes in the dash and in most cases we can utilize a "blank" switch position.  Much neater!  An electronic switch system in the end allows you to mount your switches anywhere.