Rear e-diff retrofit to MY12 4.4 TDV8

[Graeme]

Research reveals that for my vehicle there is only 1 harness specific to the rear e-diff. The various main harnesses don't nominate open or locking diff whereas the EPB harness is with or without locking diff and with or without the FBH. No harness is listed for my vehicle's missing 40A power and earth connections to the control unit, which I had earlier expected to be already fitted.

The control module has the same part number as fitted to D4s and MY10+ RRS but a control module will require calibration if not the one from the actual donor vehicle as the e-diff. The CCF will need to be changed to reflect the existence of the e-diff then the control unit calibrated to the e-diff if necessary.

Having found a complete 4.4 TDV8 e-diff and control module that is about to purchased (now secured), it's time to sort out the electrical requirements. Today the main harness connector was uncovered, containing both the can-bus wires and the ignition feed (plus another as-yet unidentified wire, not used by D4s) in an in-line connector.

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The control unit has the can-bus wires in 1 connector, the ignition feed and the 40A power and earth wires in a 2nd connector and the e-diff control wires in a 3rd connector. Therefore the wires in the in-line connector have to split to 2 connectors yet the 2nd connector should also have the 40A power and earth wires which don't currently exist. As the cost of the combination harness is around 100 GBP yet the version without e-diff support at less than 70 GBP, I now suspect that the combination harness includes the other half of the in-line connector, the 2 control unit power and can-bus connectors, the missing 40A power and earth cables and the harness connecting the control unit to the e-diff, along with the EPB and FBH harness. I will order the replacement EPB/FBH/e-diff harness as soon as the diff is on its way and hopefully my analysis holds true.

[33chinacars]

At one stage I had hoped that the E-diff could be retro fitted to the earlier TD6. Activated by a simple on/ off switch . But then from the way I believe the factory E- diff works this probable not possible. Will be following your instelation with interest

[Grentarc]

At one stage I had hoped that the E-diff could be retro fitted to the earlier TD6. Activated by a simple on/ off switch . But then from the way I believe the factory E- diff works this probable not possible. Will be following your instelation with interest

If you want an electronic rear diff lock, look at Harrop/Eaton E-Lockers - see if they make one for the earlier L322s?

Edit- after having a think about it, I am sure someone could come up with an Arduino board to run the OE diff motor - whether it is a worthwhile exercise or not is another question.

[Graeme]

For earlier models, I expected that with the different diffs fitted over the model run that the rear drive-shafts and cross-member would be different but not so, as the part numbers are unchanged. The tail-shafts are different but might still bolt-up to the flange. Obviously the diff ratio would have to match the front - 4.2SC e-diffs are readily available but their ratio could easily be different so might have to also fit the 4.2SC front diff. Otherwise wires would be needed to operate the brake solenoid, wires for the motor (expected to need to be reversible), power, earth and logic to interpret the hall-effect limit switches with the control module powered with the ignition. No need IMO for temp sensors to be working for simple engaged/disengaged operation.

[CSBrisie]

sorry I'm not down your way so you can take a peek at my e-diff...I will have to find a reason for a long drive to visit! :p

[Graeme]

This is what I bought. It will need a good clean to get through customs.
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The way my lane is shaping-up it may not come quickly enough, having to give the throttle a good jab at one spot to avoid slipping off into the gutter.

[RR44TDV8]

Bit off topic but I was going to give you a shout last week Graeme, I drove my RR from Sydney to Adelaide on Wednesday and back again on Saturday and went thru Wagga ? Man it was so green out there.....all the way across the plain, it was like someone's front lawn! Had I a little more time, I would have dropped in......I did wave as I went thru Wagga and then when I saw some black faced sheep out on the plain. Are they Suffolks?

[Pedro_The_Swift]

no wonder they weigh so much,,
I hope you have a mate to help lift that Graeme!:p

[Graeme]

...I did wave as I went thru Wagga and then when I saw some black faced sheep out on the plain. Are they Suffolks?Solid black face and feet are most likely Suffolk whereas slightly mottled faces could be South Suffolk or a Suffolk cross. The black feet better handle wet conditions on flat country. Its been a very wet winter in this part of the country but is often very green in late winter anyway.

I was in Wagga Wed morning and nearby twice in the evening but your arms would need to be long to be seen from home 40K to the north, just off the Narrandera/Coolamon/Junee/Gundagai route. Dropping by would have been a good test of your tyres in deep mud but we took the van for a run Thurs-Sat so may not have been home anyway.

Pedro, I will be using a trolley jack - it reportedly weights 60 kg! But keep it quiet that I intend to ask son Justin with the D4 to help.

The diff and RDCU are on their way - hopefully they don't get lost en-route from St Peterburg.

[Grentarc]

Pedro, I will be using a trolley jack - it reportedly weights 60 kg! But keep it quiet that I intend to ask son Justin with the D4 to help.

Good thing I stopped paying attention after you mentioned 60 kg!

[Graeme]

The e-diff arrived at the depot today so as I was going to town anyway, I took the trailer. I'm not sure about the 60kg as I lifted it onto the rear of the trailer but it isn't particularly light. The control unit is marked as being from a D4 and is without the L322 mounting bracket so some porkies were told, therefore I'll have to make a bracket and have the diff calibrated prior to use but intended to anyway. The inside of the diff looks clean although the outside needs a scrub with a wire brush and some fresh paint.

The replacement wiring harness for the epb/fbh pump that includes the e-diff and new drive-shaft seals and circlips also arrived today. However hurdle #1 has surfaced, being that the harness does not include the 3 connectors for the control unit, with the wires for the 3 facilities terminating primarily in 1 connector but power and earth in a 2nd connector. I have sought clarification from Duckworths regarding a possible 2nd harness that my version of the parts catalogue doesn't show, but perhaps there are different main harnesses with and without e-diff support that the parts catalogue doesn't show. Worst case will be the need to acquire the 3 control unit connectors either as new shells or from a wrecked vehicle with an e-diff and make-up the missing harness myself. As the terminating connector is the same as one of my Llams kit connectors, I already have extra pins if needed for the existing plug.

[Graeme]

One step closer today, having found the mating connector for the replacement under vehicle harness.
113105

The connectors for the control unit will be in the harness that runs across the rear to the fuse panel and because of all the wires and connectors in that bundle and therefore the expected high cost, I will obtain the connector shells for the control unit and make my own harness. The plug in the picture requires some extra pins but as the plug is the same as one of the LLAMS loom plugs, I have ready access to the required pins. I expect to have sockets for the control unit pins as they are the same as the large pins in the plug in the picture so have plenty of those from discarded early LLAMS looms. The plan is developing well.

Edit: The connector part numbers have been identified and will cost around GBP 20 for 4 connectors plus shipping. Wiring diagrams have been retrieved.

[Garfield]

Just out of interest I went to the 4WD show last week in Melb and asked at the Harrop stand whether they had made up a E diff that could be retro fitted to the back of a late model D4. The basic answer was no, too difficult to get it to integrate with the TC. ( expected answer )


So will just have to make up with my poor 4WD driving skill :D


Sorry, I know I have ventured off the forum topic

[Graeme]

The RDCU connectors are of the same family as the TCCU connectors so I'm chasing a set of TCCU connectors from a D3/D4/RRS/RRV to re-use their sockets in new RDCU connector shells because a certain wreckers wants an arm and a leg for a used set of the RDCU connectors with short wires attached - a captive market for e-diff retrofits they think. A bonus is that one of the TCCU connectors is the same part# as one of the RDCU connectors. The folks at British Off-Road are being very helpful.

[Graeme]

The TCCM connectors/wires didn't work out as I haven't been able to remove the sockets without the special tool. I'm sourcing new sockets and the plug not ordered with the others and for half the cost of the TCCM connectors, so should have stuck with my original plans. I'll note the part numbers and suppliers at the end of the project along with the rest of the details.

[Graeme]

I could have done with the e-diff today but it's still sitting in the shed so had to make TC work overtime. The lane didn't fare well yesterday with a dozen or so 4wds some with trailers coming then going, chopping up mud-holes that my neighbour and I had been nursing by only slowly wading through. I was gently working my way along the edge quite well when the 2 right wheels dropped into deep holes stopping forward progress.

114272

Clearance wasn't an issue, already at off-road +30mm, just lacking traction on 1 side. A few back and forth rockings then some right foot whilst in mud n ruts got it going but not before my wife thought that we were stuck fast. It would have been OK though as we had a toilet in tow, if only we could get to it. Oh yes, the neighbour rang later today saying that his Prado had grounded its diffs a little earlier although it wasn't still in the mud-hole when I went through later with my box trailer with a few rams on board, so presumably he freed himself too.

[rar110]

Nice looking place there Graeme. But that part of the lane looks like it needs about $10k worth of rock and road base. Maybe you've done that and it's sunk into the clay. I've had that experience.

[Piddler]

Nice looking place there Graeme. But that part of the lane looks like it needs about $10k worth of rock and road base. Maybe you've done that and it's sunk into the clay. I've had that experience.

Yep me agrees :cool:, money needs to be spent on access.

lovely country and nice to see some moisture after all the years of dry.

Cheers

[Graeme]

This section is the latest to succumb to the water draining from the soil profile, with others previously patched with large blue-metal or drains dug with more spots already very messy. It has been an unusually wet winter though and droughts or dry springs are recent memories where dust and locusts was the scene.

[chaybra]

diff clearance is extremely under rated!

Mine is sitting at over 15", well and truely more than a patrol on 35"s

[Graeme]

The patch can't be too bad as a 2wd Territory made it through after almost all the others, but I know how he drives mud in his employer's vehicle...

[Graeme]

All connectors and contacts are now on hand. Can-bus wires are nearby for the EPB module. Ideally the ignition feed would be picked-up from the original wire that supplies all transmission modules but will use the nearby EPB ignition feed.

It's time to mount the control module so that wiring can commence.

[Graeme]

The control module has a home - nothing moved and using an existing bolt hole.

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The control unit wiring harness is finished except for cutting the main power wire to length then fitting a 9.5mm female spade terminal to fit to the empty cavity in the connector in the rear fuse panel. A temporary EPB/FFH/e-diff connector is fitted to allow testing with the new external harness prior to fitting the diff itself. After testing, the pins will be transferred to the existing connector's vacant cavities and the new external EPB/FFH/e-diff harness will replace the current EPB/FFH harness. The free can-bus and IGN feed wires need to be attached to existing wires in the same connector.

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[Graeme]

The diff was test connected to the vehicle today - in a wheel barrow behind the vehicle. A permanent clutch fault exists even though the clutch can be operated directly and there is 12V at the clutch pins in the diff connector. The fault may be due to the module and diff being from different vehicles and not yet calibrated so will get that done before looking further.

I minor hiccup was due to having fitted the canbus pins in the reverse order due to misreading the circuit diagram and ignoring the crossed lines close to the module. I now suspect the reason the transfer case control module is a canbus gateway is to keep the engine, brakes, gearbox and transfer case operating if a fault develops in the HS canbus further back in the vehicle, as the crossed wires shut down all the modules on the rear side of the TCCM.

[chaybra]

The diff was test connected to the vehicle today - in a wheel barrow behind the vehicle. A permanent clutch fault exists even though the clutch can be operated directly and there is 12V at the clutch pins in the diff connector. The fault may be due to the module and diff being from different vehicles and not yet calibrated so will get that done before looking further.

I minor hiccup was due to having fitted the canbus pins in the reverse order due to misreading the circuit diagram and ignoring the crossed lines close to the module. I now suspect the reason the transfer case control module is a canbus gateway is to keep the engine, brakes, gearbox and transfer case operating if a fault develops in the HS canbus further back in the vehicle, as the crossed wires shut down all the modules on the rear side of the TCCM.

You can switch the diff lock on and off without the computer you say??

[Grentarc]

You can switch the diff lock on and off without the computer you say??
I am pretty sure I know what you are thinking, but the LR E-Diff is a progressively locking clutch system (whereas the Harrop e-diff is an electromagnetic locking centre) that the RDCU "learns" the open and closed limits required. If you didn't have those limits, you could run the risk of not having the diff fully open for normal driving

[chaybra]

I am pretty sure I know what you are thinking, but the LR E-Diff is a progressively locking clutch system (whereas the Harrop e-diff is an electromagnetic locking centre) that the RDCU "learns" the open and closed limits required. If you didn't have those limits, you could run the risk of not having the diff fully open for normal driving

What type of signal controls the locker? Is it a single feed to a spring returned clutch? or a full stepper motor?

Either way, a simple arduino board could control to either full lock or full disengage?

[Graeme]

The e-diff uses a motor that turns either direction, a clutch that I suspect holds the motor or the mechanism to prevent turning and limit sensors. I expect that a simple control module could be programmed to operate the motor to the fully unlocked or fully locked position by honouring the limit sensors.

Obviously an e-diff would have to be the same ratio as the front diff.

[Graeme]

My vehicle now reports/displays that it is fitted with an e-diff even though only the control unit is installed. No warning messages are displayed in rock crawl or when booting it in mud n ruts although the instrument cluster now shows the rear diff symbol but always unlocked whereas the centre diff shows locked.

I could have done with the e-diff again earlier today when progress at off-road height + Llams high was temporarily halted whilst crossed-up in deep, gravely bog-holes in the road, left after another 4wd was extricated on the w/e. Some back and forth shuffling then significant right boot, TC and lots of scraping noises saw the vehicle moving again.

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[chaybra]

Great forward moving with the project mate! Glad to see its all fitting into place!

Once you have swapped out the housings, be sure to strip down the old one and get some decent measurements of it and help the rest of us (because finding a standard Ediff is near impossible) match one up with another vehicles diff!

[Graeme]

The fault code P0900 that refers to open circuit on the brake clutch is also used for open circuit on the motor, discovered when my elder son rechecked the connectors in my fabricated section of loom and found that I had fitted the motor earth wire to an unused cavity, causing an open circuit for the motor. Correcting the motor wiring has overcome the reported clutch circuit fault and now both the motor and the brake clutch click momentarily each time the ignition is switched on or off, so more progress.

The only pre-fitting task left now is to have the module perform a self-check to calibrate. Clearing the module's faults after the motor wiring was fixed caused an unusual series of clicking noises from the diff compared with the short on/off clicking noises that now occur. It's plausible that the control unit may have done a calibration at this time but without any reference from other sources I cannot assume that the calibration has been done. The Faultmate Extreme doesn't currently support the self-check function even though some preliminary work has been done so I may have to piggy-back a subscription for my L322 onto an IID Tool.

Edit: As the e-diff has been successfully connected to the vehicle for a few ignition cycles and therefore no possibility of still being locked, the internal wiring will be finalised then reconnected to the e-diff to ensure pins have been transferred to the existing connector properly. The next step will be to swap diffs then swap the external harness but leave the fuse removed until calibration can be done as it will be safe to drive whilst waiting for a calibration.

[Graeme]

The e-diff uses a motor that turns either direction...My earlier post on the e-diff's mechanical operation is incorrect and should be ignored.

[Graeme]

A final out-of-vehicle test was to check that the diff showed locked in rock-crawl, which it did. Then after the pins were transferred from the temporary connector to the vehicle's connector the diff wouldn't show locked, presumably because the EPB had been disconnected to use the new external loom. The earlier test required the tail-gate locks to be closed before it would lock so no EPB is a plausible excuse. Next task is to re-paint the diff after cleaning-up the rust, corrosion and yellow paint that was applied to all bolts, nuts etc by the dismantlers.

[Graeme]

RDCU connector housings (no contacts) can be bought from LR dealers or independent parts suppliers in the UK using the YPC numbers or from connector suppliers using the Tyco numbers. The connectors can be fitted with a secondary locking pin although LR don't always use them.

YPC114190 Tyco 1-967623-1 lock pin 967633-1 Purple 15-pin
YPC114170 Tyco 1-967621-1 lock pin 967631-1 Yellow 9-pin
YPC800350 Tyco 1355204-1 lock pin 967634-1 Black 17/18-pin (locator at pin 15)

As LR spare parts the yellow housing costs 10 GBP and the other 2 less than 3 GBP each. The yellow housing incl lock pin from Element14 was $1.26. Postage was the biggest cost.

I bought 30 965999-2 (30A, highest rating) contacts from Element14, Farnell UK's Australian operation for $7.15. 19 are required and I wanted more than 1 spare, not that there was a minimum or multiple order quantity. I found the contacts impossible to remove, not having the $45+frt special tool. I soldered the wires to the contacts as crimping would have required the very expensive special tool and multiple contact sizes for the mix of wire sizes.

The RDCU must be for the correct canbus version. Mine happens to be from a D4, only known by the markings applied by the dismantlers.

[BobD]

Its just as well it's you doing this Graeme. Anyone else would have enormous trouble and I bet it's absorbing a lot of your time. Do I detect another kit for retrofitting ED's coming out of this work? It would probably make a lot of people happy!!


I hope the RDCU is not as sensitive to the Can Bus version as the EPB is. An EPB from a later model car wouldn't work on my D4 because the Can Bus has been changed from my early 2010 model D4. We had to get the correct one for the VIN to get it to work.

[isuzurover]

I commend you on all the hard work. If it was me I think I would have just developed a standalone aftermarket controller...

[Graeme]

The control unit part number is the same for D4s at least to MY12, MY10+ L320 and MY10-12 L322 and they all run the same s/w version. I consider that the system is working, just that the diff hasn't been fitted and calibrated yet. The diff showed as being locked when rock-crawl was selected so the control module was happy that it was communicating correctly with the diff electrics as required. Moving between neutral and drive caused clicking noises from the diff so with no faults now being recorded, I consider that all is well.

The canbus tappings can be anywhere on the HS canbus but IMO best that it be on the rear section as per the original wiring. The park brake canbus wires are conveniently in the same connector that the RDCU uses to communicate with the diff.

Buying new connector housings and new terminals is very inexpensive. A well-known wreckers wanted $175 for a used set with 150mm of wire from a wreck, justifying their asking price on their lack of availability and the cost of a crimping tool.

Being able to purchase the L322 harness that connects the EPB and the e-diff to the main chassis harness makes for a neat installation under the vehicle. However the complete harness could easily be fabricated providing the e-diff is purchased with both electrical connectors fitted - mine only had the main connector so the oil temperature sensor connector would have to be sourced.

I consider the retrofit is a straight-forward task and would be happy to provide insight gained to others.

[Milton477]

Great job! I admire your ingenuity.

[carlschmid2002]

When I was shopping for a used D4 I would have opened up my search knowing that this could be possible down the track. Great work.

[Graeme]

An expensive retrofit compared with the original extra cost if buying new and perhaps no extra cost if buying s/h especially if the seller isn't aware that an e-diff is fitted.

[carlschmid2002]

An expensive retrofit compared with the original extra cost if buying new and perhaps no extra cost if buying s/h especially if the seller isn't aware that an e-diff is fitted.

I doubt my D4 V8 has ever seen a dirt road before I bought it. I still haven't activated the E-Diff.

[Graeme]

From observations done by my son Justin using his IIDtool, his e-diff engages to a degree every time his D4 drives-off even with TR in normal mode. It appears that e-diffs get a lot more use than expected.

[Grentarc]

From observations done by my son Justin using his IIDtool, his e-diff engages to a degree every time his D4 drives-off even with TR in normal mode. It appears that e-diffs get a lot more use than expected.
I was just about to post this information!

I might hook the IID Tool up tomorrow to log the e-diff on a normal drive.

[CSBrisie]

I can confirm this Graeme - the red padlock indicator on mine shows frequently when I'm off road with TR in any mode other than normal.

[isuzurover]

So apart from electronic troubleshooting, how do you confirm the diff is "locking" properly and the clutch pack isn't worn out?

Has anyone worked out how to shim them up tighter like people do with LSDs?

[Graeme]

The clutch packs are self-adjusting when a diagnostic self-test/calibrate request is issued by an appropriate tool.

A business in the USA that rebuilds the e-diffs reports that the clutch components are very robust, only requiring a good clean and new bearings and seals when moisture accumulates from inadequate oil changes in very cold conditions

[Grentarc]

I was just about to post this information!

I might hook the IID Tool up tomorrow to log the e-diff on a normal drive.

Here is the log of a D4 e-diff on a normal drive to drop my son off at childcare this morning

http://www.waggafish.com/edifflog.pdf

[Graeme]

Please explain!

I expect that the e-diff gets armed ready to prevent wheel-spin on every straight-line take-off - I doubt that it's fitted as standard equipment to SC L322s to maximise their off-road capability.

[Grentarc]

Please explain!

I expect that the e-diff gets armed ready to prevent wheel-spin on every straight-line take-off - I doubt that it's fitted as standard equipment to SC L322s to maximise their off-road capability.
There is only 1 standing start in that graph, all the rest were rolling starts, so it doesn't load up the diff as much - the standing start you can see goes up to almost 500Nm of lock, which was a gentle takeoff from some traffic lights. I will log another one now with similar distance, but will log it against speed as well.

[Grentarc]

Here is a screenshot of the log, the last log had steering angle to see if that affected diff loading, and this one has speed and current gear instead.
You can see that when starting from a standstill, the diff is loaded up to almost 500Nm - and all this is without any TR setting selected.

https://www.aulro.com/afvb/images/imported/2016/10/92.jpg

[isuzurover]

Here is a screenshot of the log, the last log had steering angle to see if that affected diff loading, and this one has speed and current gear instead.
You can see that when starting from a standstill, the diff is loaded up to almost 500Nm - and all this is without any TR setting selected.

https://www.aulro.com/afvb/images/imported/2016/10/92.jpg

So it really only turns on twice in that plot.
Anything below 50 Nm could be regarded as off.

Presumably like most active diffs it is responding to throttle, steering and wheel speed inputs.

[Grentarc]

So it really only turns on twice in that plot.
Anything below 50 Nm could be regarded as off.

Presumably like most active diffs it is responding to throttle, steering and wheel speed inputs.

Yes, although it shows that it is not just reacting to loss of traction, it is loading up the diff preemptively. I will do more logs of the diff behavior in different TR settings etc one day - but here is the PDF of this latest log so that you can see the individual values easier (it shows 5 activations rather than just the 2 big ones)

http://www.waggafish.com/ediff2.pdf

[isuzurover]

Yes, although it shows that it is not just reacting to loss of traction, it is loading up the diff preemptively. ...

That makes sense though. Proactive rather than reactive gives a much better driving experience. Just compare it to [brake-type] traction control systems.

[Grentarc]

That makes sense though. Proactive rather than reactive gives a much better driving experience. Just compare it to [brake-type] traction control systems.
Exactly - and it is the reason why I have noticed with my D4 that it takes a lot for TC to activate in mud etc.

[Graeme]

The diff swap was accomplished last Saturday week. It was definitely a 2-person job to pull the drive-shafts out far enough to clear the diff seals and not so easy to get the e-diff in position either so lots of thanks to Justin. The new version of the epb/fbh pump/ediff wiring harness was installed the next day but hindsight indicated that it should have been fitted before fitting the e-diff due to quite difficult access to disconnect and reconnect the epb connector. The ediff motor was left disconnected until a new IIDTool arrived this afternoon as my Faultmate Extreme does not have the option to calibrate the ediff.

The e-diff is now operational. In rock crawl the IIDTool shows 495 Nm target and current torque whilst in reverse and stationary and 1200 Nm target and current torque in drive and stationary. The instrument cluster and 4x4 display show the rear diff is unlocked in reverse but locked in neutral and drive. All done!

[BobD]

Good work Graeme. Not many people would have the understanding of these systems that you have.

Are you now going to add an e diff conversion kit to your list of Land Rover products? You could make a fortune, especially since hardly any Rangies have e diffs! I'm sure that you would love to offer a fitting service as well (Not).

[CSBrisie]

Amazing job Graeme (and Justin!) and no doubt the envy of many owners of recent LR models (well esp those without an e-diff!!)!!

[Graeme]

Bob, I'm happy to help people with the process of sourcing connector shells and pins and fabricating and installing the extra wiring but wont be providing any kits. The task is simple in principle due to the diff control being can-bus based but there are different wiring courses for the L322 vs D3/4.

On that topic, I was surprised to find that after having connected the wiring harness and RDCU power supply to have an operational albeit inappropriately calibrated system that the ABS objected with TC, HDC, ESC and EBD faults and the ABS and suspension ecu logged comms faults for the RDCU when the power was subsequently removed from the control unit. This indicated that the ABS and suspension ecus modify their operation once a working e-diff is detected, compared with my expectation that ABS simply didn't have to do as much work if an e-diff prevented wheel-slip.

[Grentarc]

I'm sure that you would love to offer a fitting service as well (Not).

I definitely made the statement after helping fit this one that I was in no hurry to do that again.

[Graeme]

Having driven through sloppy stuff very recently I've noticed quite a change in the vehicle's behaviour and more than I expected. It progresses smoothly through the slops as though the ground is firm, now without any hint of sideways movement of the rear-end and without any reduction in speed. With mud'n'ruts selected the rear diff often showed locked for quite some distance and speed, with the centre diff generally showing locked later and releasing sooner. It's now time to forget about it and let it do its job.

[rar110]

Fantastic.

[Graeme]

Yes, I'm amused that I can detect the difference whilst not in extreme conditions. I recall noting the L322 feeling loose in such conditions when first driving it compared with the D4 but with different suspensions the difference could not conclusively be attributed to the lack of an e-diff.

[Graeme]

The car has had intermittent EPB electrical issues for the last year or 2 which seemed to be cured by refitting the EPB plug but only for a while after which different DTCs occured, including U0417-81 (AF) from the CCM module (? - the 4.4 TDV8's PCM handles CC) that prevented the use of cruise control. The latest faults only occurred after wake-up so a restart was necessary to use CC. I removed the plug again today after having done so a week ago and spotted a very short section of chaffed wire. I hadn't inserted the harness restraining fitting to its hole when I fitted the e-diff 8+ years ago so this wire had rubbed on the subframe. I had fitted the restraining fitting a week ago to avoid possible future problems, but a few years too late. The wire is the status wire.

[gentleman_driver]

Hi Graeme - this is an incredible undertaking! The rear diff lock is the one feature motivating me to look at other vehicles. I have a 2012 HSE w/o locker and my father has the same exact model with it optioned (a unicorn 5.0 NA, not SC, with the optioned rear locker). When we off-road together, he walks up obstacles much easier than mine despite me having fitted 275 65 18 BFG KO2s… (FYI did the Terrafirma wheel adapters and refinished LR3 18” wheels)
If I could retrofit a locker then I think I would keep this vehicle forever. I’ve found a salvage yard here in the US that is selling good order rear lockers with the 3.54 gear set from 2010-2012 models, however, I would also need to acquire the RDCU and requisite wiring.
Do you perhaps have a list of all of the parts I would need to transfer from a salvaged L322 2010-2012 with rear locker to my vehicle? I assume it is more than just the diff, diff motor (which is coming on the diff already), RDCU, and wiring into the RDCU and out to the diff…
I’ve read your thread here and at fullfatrr.com, and am grateful for your inspiration!
Cheers from the US

Michael

[Graeme]

The wiring harness to the e-diff includes the EPB harness and the FBH pump harness. The harness connects inside the vehicle to one that includes the wires to the RDCU which is located under the carpet under the left side of the rear seat as well as to the harness that runs across the rear to the electrical panel in the right corner. If you can't extract that harness then at least get the RDCU and the attached harness back to the connector and the connector itself so that you can merge the RDCU harness into your connector, then install your own power cable back to the fuse panel and fit the fuse. The connector is easy to dismantle. There is a heavy earth wire for the RDCU which will be bolted somewhere nearby so try to get that too.

The RDCU from an early LR4 is identical but getting the wiring from the donor vehicle will save you having to get connector shells and terminals to fabricate the harness.

The diff is heavy, best changed on a hoist using a mount on a stand to hold the diff rather than 2 people struggling with multiple jacks and blocks of wood on the ground, as it's a long way up with the vehicle high enough to work under.

[gentleman_driver]

Amazing, thank you Graeme! And is the Topix manual the best place for instructions? I need to figure out how to download for a car with the features I don’t have… will need to dig up a VIN with a rear locker (maybe I use my dad’s…)

[Graeme]

Amazing, thank you Graeme! And is the Topix manual the best place for instructions? I need to figure out how to download for a car with the features I don’t have… will need to dig up a VIN with a rear locker (maybe I use my dad’s…)
I'll dig out the couple of CCF settings that need to be changed.

[Graeme]

Sorry, I forgot to look at the CCF changes until just now.
The only CCF change was to change the rear e-diff from not fitted to fitted.

[Pedro_The_Swift]

The E Diff is amazing,, on gravel roads the car just launches :eek2:( dash cam would be interesting!)