Thread: D4 ARB Front Diff Lock: Anyone?

As far as I'm aware, the ARB front locker is only available for the 2.7l D3/D4 and the rear locker is only available for the D3, apparently there were issues when fitting the rear locker into the D4, I have no idea what that issue was, but it could be the fact that the rear diff in the D4 maybe different, you'd have to call ARB Head Office for that.

Originally Posted by Dr LC8

In my case I have a 8 gear SDV6 model with no rear Active Locking Differential. My one was second hand and it is an accessory that very few add to their specs in the UK.
Unfortunately it can't be retrofit...

It can be retrofitted if you're keen enough - my MY12 L322 now has an e-diff.

Originally Posted by Graeme

It can be retrofitted if you're keen enough - my MY12 L322 now has an e-diff.

Is there a thread detailing the process by any chance Graeme?

Thanks Graeme,

Looking on forums and enquiring experts directly (mudtech4x4 and prospeed) none of them is prepared to do it. I found a second hand e-diff but, as I said, no one will fit it.
They don't think is worth doing it.

There is a thread will full write ups and instructions on disco3.uk somewhere on how to retro-fit the diff lock. Hardest part sounds to be getting the wiring looms sorted, but certainly not impossible.

Originally Posted by TuffRR

There is a thread will full write ups and instructions on disco3.uk somewhere on how to retro-fit the diff lock. Hardest part sounds to be getting the wiring looms sorted, but certainly not impossible.

Thanks, I know it. It was written by the guy who owns and develop www.mudtech4x4.com I wrote to him. He didn't say that it didn't work, but he said that they are thinking to develop a system but they haven't done any progress so far.

Retrofitting an e-diff to my L322 was slightly simpler than to a D3/D4 as far as I can see in that the L322's wiring harness to the e-diff is a distinct section of a multi-function loom for which the e-diff included version can be purchased, although wires with connector pins have to be inserted in the other half of the connector to continue to the e-diff control unit. Discos use a completely different rear chassis harness that does or does not include the e-diff wires but that only means that a wiring loom between the e-diff and the control unit has to be fabricated, best done by obtaining the under-vehicle section from a wreck then adding control unit connectors. Control unit connectors can be purchased as LR spare parts and the connector pins obtained from connector suppliers.

Integrating the control unit is simple, requiring connecting to the HS canbus anywhere but most readily en-route to the EPB module, permanent 40A fused power, ignition power and earth. The CCF has to be updated to reflect its existence and a calibration done if not using the control unit out of the same vehicle as the e-diff, both using a suitable diagnostic tool.

For a Disco the drive-shafts should be upgraded to the heavier duty e-diff version so acquire those along with the e-diff (with the correct ratio) and the control unit. D3 control units are unsuitable for D4s due to different canbus protocols and the same applies to L322s up to MY09 vs MY10-12.

Even doing the work oneself, the retrofit could be quite expensive so for most people it's unlikely to be worthwhile.

Here is a link to my L322 retrofit thread.
Rear e-diff retrofit to MY12 4.4 TDV8

Originally Posted by Graeme

Retrofitting an e-diff to my L322 was slightly simpler than to a D3/D4 as far as I can see in that the L322's wiring harness to the e-diff is a distinct section of a multi-function loom for which the e-diff included version can be purchased, although wires with connector pins have to be inserted in the other half of the connector to continue to the e-diff control unit. Discos use a completely different rear chassis harness that does or does not include the e-diff wires but that only means that a wiring loom between the e-diff and the control unit has to be fabricated, best done by obtaining the under-vehicle section from a wreck then adding control unit connectors. Control unit connectors can be purchased as LR spare parts and the connector pins obtained from connector suppliers.

Integrating the control unit is simple, requiring connecting to the HS canbus anywhere but most readily en-route to the EPB module, permanent 40A fused power, ignition power and earth. The CCF has to be updated to reflect its existence and a calibration done if not using the control unit out of the same vehicle as the e-diff, both using a suitable diagnostic tool.

For a Disco the drive-shafts should be upgraded to the heavier duty e-diff version so acquire those along with the e-diff (with the correct ratio) and the control unit. D3 control units are unsuitable for D4s due to different canbus protocols and the same applies to L322s up to MY09 vs MY10-12.

Even doing the work oneself, the retrofit could be quite expensive so for most people it's unlikely to be worthwhile.

Here is a link to my L322 retrofit thread.
Rear e-diff retrofit to MY12 4.4 TDV8

Great stuff Graeme. Awesome.

IMO most of the penalty of not having an E-Diff is that the brakes take a bashing - i.e. rotors and pads get used more. Perhaps the E-Diff is more functional too but then add the issues with the great variable being driver skill and its IMO a marginal benefit. Excluding the pad and rotor issues.