Outer Limits 4x4 Board

I'm quite excited, bought a NZ new 1999 model as a write off, been on its side but runs so sweetly, Its a LWB TDi 2.8 and being NZ new it has a Rear diff lock.
So I plan to swap this over to my 3.5 and take pic's along the way, I see a few have done this swap with some interesting ideas. Sounds like most are doing away with the ECU and switch, just running with a basic on off switch.
Can anyone tell me where the ECU for the locker is located in a LWB?

So I plan to take pics and write along the way to make it easy to do for someone later.
Right, so I understand the housings are identical for a locked and LSD'd rear end, So should I just put the guts of the locked diff in mine or swap whole disc to disc?

Thanks, GLEN

O and if anyone in NZ wants a good 2.8 TDi with service history, auto and transfer case, PM me!

Yup, the diff housings are identicle.

BUT remember in the locked version the left axle is about 7mm shorter than the standard axle., so you must use that. The right axles are the same.

Dont know where the ECu is & IMO you dont need it, so long as you can rig up some sort of safety control so that it doesnt accidently get operated on whilst travelling along fast. I use the blue ARB switches since I also have the front locker, that way all the switches are uniform.

The pump is under the rear , right side seat, but you'll be able to trace the airline back anyway.

It is really a farily easy swap over. Just make sure the diff ratios are the same & if their not the CW&P are a swap over!

Dont do what I did (initially) & just swap in the entire rear end UNLESS you know the rear end is straight. Mine was from a rear ended wreck & it was bent although you couldnt see it. Couldnt figure out why I was chewing the insides of the rear tyres until I took it to a truck alignment shop. They were amazed how much it was bent.!!

Good luck.

Thanks for that Ian,

So when you have your rear locker in, does it operate the light on the dash which is controlled by the switch inside the diff?

Sounds like that is the way I will go, use ARB switches, at some stage I will be adding a front locker.

Becasue I have 4.6 diff's and the donor has 4.9's, I think I'll fit them to mine, I know you did and didn't think it worth while. I am confident the rear housing on mine is straight

Ive read that the ECU is located in the rear passengers side, behind the plastic, somewhere near the power socket...

Does it have a woodgrain steering wheel?

interesting that it looks like its got 15" rims on it. thought all the nl's had the larger front disc's that require 16" rims ?
also an auto ! how does it drive with the auto ?
all the aus 2.8td's were manuals!
cookie monster

Hi NJ,

yes I wired it up so that when the locker is engaged the dash light is on.

Important that you check that the switch in the locker actuially works before you put it all in, cant rememeber if you need to take the diff apart to change the switch, all I recall is that it was $90 for a new switch.

Anyway once you have it all set up, its simply a matter of connecting up a switch wire from the diff switch to the light on the dash. If you take out the dash , its pretty easy , you can see which light it is. I just traced the circuit back to the wiring loom & joined it there.

Just a note though is that you need to power the diff switch from a separate source than your ARB switch. Because although you might have turned on/off your ARB switch the locker can actually take a while to lock/unlock. I think I sourced a power supply from the blue wire in the harness near where the factory pump goes, ie in the under seat compartment.

Also if you decide to use the factory locker loom & connector you must ensure the joint does not break down by movement, mine did & gave false readings, so I just cut out the factory connector & soldered all the wires together.

There is a bit of mucking around with the wiring but its all doable. Youll have to drill a 3/4 hole in the body to get the loom & air hose thru to the pump. Make sure you use a grommett so the wires etc dont get damaged.

With the diffs , yes I did swap over to 4.90s, I got all the work done by a diff shop, the front diff is a bastard to change they reckon.

I really didnt find it worth while but thats just my opinion alone.

But as you have to change , you could give it a try I guess..


Just write if you need any more help.
cheers

OK, I tried the locker again on the donor vehicle and everything works. The compressor does squeal a bit thou, I haven't had a look to see if anything can be oiled or what not - any suggestions?

cookie monster wrote:interesting that it looks like its got 15" rims on it. thought all the nl's had the larger front disc's that require 16" rims ?
also an auto ! how does it drive with the auto ?
all the aus 2.8td's were manuals!
cookie monster

Yes it does have 15's on it, it all looks identical to my '94 under there. I never really got a chance to drive it with the auto but Turbo Diesel's and auto's seem to work quite well. I did sneak a drive up the road one evening (its not registered and is a bit twisted with no windscrean!) And it went nicely, the auto just keeps the diesel in it's sweet spot and you never notice any off boost sluggishness.

NJV6 wrote:OK, I tried the locker again on the donor vehicle and everything works. The compressor does squeal a bit thou, I haven't had a look to see if anything can be oiled or what not - any suggestions?

Hmmm compressor dont normally squeal, it does sort of buzz when its on, but it turns off once pressure is reached.

Does yours eventually go off or does it stay on all time, ie makes a noise all the time.

Yes it switched off after about 5 to 7 seconds. (ish)

Engine is now sold and out. Been keeping busy with work so things haven't progresses so quickly but the inside is now all but gutted


The air pump was smaller than I was expecting - mind you I don't really know what i was expecting


The ECU comes from here


Which was the results of following many wires!


all followed back from the lock switch & pump.

You shouldn't need the wiring, the looms are already in the vehicle.
I just finished fitting a 4.9 to a 3.5 manual and all the wiring was there except the loom down the rear arm to the diff head.
I have also fitted a 5.29 locker to a 92 3.0 V6 and that was the same.
If you have ABS there are a few differences as I discovered to my cost, some axles don't interchange between housings.
J Top

Yep, the following of wires was just to check that ECU was the right one - There are many many ecu's & relays!

The 3.5 you have just done, did you use the ECU or just wire it to a switch?
Tell me more about this ABS - My V6 doesn't but the donor vehicle does.... I was intending to swap disc to disc and i think you have just made up my mind for me....

NJV6

The owner wanted to retain the ECU . If the ABS collars are on the axle next to the bearing collar the earlier difffs won't accept the axle.
J Top

Latest efforts.

My 3.5 SWB manual was the one J Top just finished fitting the rear locker to. I decided to retain the factory ECU and compressor as I couldn't see any sense in spending more $ fitting an ARB compressor on the chance I might fit a front locker (esp since we were just swapping it from my LWB 2.8TDi and some had all the parts needed).

I also did some testing of the rear locker in the LWB prior to removing for the 3.5 SWB. Results are below:

Rear Diff Lock only engages in either 4HLc (4wd High Locked centre) or 4LLc (4wd Low Locked centre).
Rear Diff Lock engages only below abt 10km/hr. It seems to pump up pressure but doesn't feed it to the locker until speed reduces abt 10km/hr.
In 4HLc, in 4th Gear, I took the vehicle up to 100km/hr (in a straight line) and the Rear Diff Lock stayed locked.
In 4LLc, in 5th Gear, I took the vehicle up to 80km/hr (in a straight line) and the Rear Diff Lock stayed locked.

So..... it appears that while the ECU controls when the Rear Diff Lock is engaged (below 10km/hr), it doesn't appear to dis-engage the diff lock at any speed (or at least below 100km/hr as tested).

So I could only see positives retaining the ECU both in cost (wiring already there) and safety (enaging the locker accidentily on the road at speed etc...)

Given the issue we had with the locker axles not fitting the 3.5 SWB (which is a 94 like urs) I would recommend doing a complete rear end swap.

Cheers.

Thanks for your reply Kiwijero, sounds like we have the same vehicles. Did you change the front diff sub frame and everthing over or just the crown wheel and pinion?

And also did the factory ECU plug into the SWB loom in the same place as where the LWB one unplugged from?

Yes same year & model...... only had this for a couple of months, straight off the boat from Japan !!

I sourced a complete 4.90 front diff housing to go into the 3.5 SWB (along with the rear LSD and axles for the LWB 2.8TDi), a lot easier to do a complete swap out than change the crown wheel & pinion.

On the SWB, there was already another ECU on a mounting board with space for another two ECU's (mounting bolts already there) in the middle of the rear wall on the left side.
The compressor must mount somwhere in the wall between there and the passenger door pillar, but must use a different mounting to the one used in the LWB position (under right rear passenger seat) so we mounted the compressor beside the ECU's and ran tubing along the wall, down pillar and out through the body under the seat (same position as the LWB), using the rubber plug from the LWB.
Also used the joiner (where the small pressure tubing changes to a thick hose down to the diff head connector) from the LWB, bolting it to the centre rear seat bolts that come down thru the floor (used longer bolts) underneath.
Cheers
Kiwijero

Well after a big weekends work I have the diffs changed over. Getting them out of the donor was easy as no body or engine to get out ofthe way but mine was a bit harder.

Not to mention the back ends on these are so blinkin heavy its not funny! drove into the workshop at 8:30am. To do the entire swap for the rear was about 3.5 hours (not including fitting the compressor etc).

The front diff was not so much fun having not had an independant end to bits before I was just feeling my way a little to begin. After getting the ball joints the cv came out of the diff not to bad & other side unbolted easily. After deciding the crossmember needed to come out the diff came out but it is bloody heavy as well.
In with the 4.9 one and fixed in place only to discover the bolt holes for the right hand cv are different so my cv wouldn't bolt up to it!
And having read they were the same I didn't have the 4.9cv with me - a 2 hour return trip to Invercargill had the right cv and after 5.5 hours I had the front one in and drove it out of the shed.

Then remembered I had no brakes - or at least limited brakes and no handbrake! I was hoping to use the LWB handbrake cable because I feel the SWB handbrake comes on on full articutation and hinders travel a little. The LWB cable is very long however and I guess I'll change back. Anyone else done this?
Next weekends job is to bleed brakes, fit handbrake and compressor, ECU, etc & take it for a wee spin.

I ran LWB cables on mine, but with a 3" body lift, I also found the SWB cables pulling out of their body mounts on artic. The LWB cables have a loop in them at ride height but saved me about $110 a cable having them made.
J Top

Ok, I have got the locker in and working, I didn't have enough air line before.

A couple of questions - I am not quite sure all is well.

The pump flicks on and off for less than a second at about 5 second intervals once the light on the dash goes solid. I am guessing an air leak?

Next question, when I turn the key on the light flashes for a couple of seconds when not in 4WD. It also takes a good 10 secs to engage (according to the dash light) when quietly driving around which seems excessively long.

Any thoughts?

Glen

yeah mine does that too some times, I have checked & rechecked for an air leak but cant find one. Could be a faulty pumP?? but they aint cheap new , let me tell you!.


Also the diff can take a bit of time to lock & unlock sometimes, but usually no more that a minute or so. Reversing & forwarding helps as well

cheers

Glen

I havn't heard my factory rear locker pump come on again once it has locked in. As it locks it does sometimes come on agains so must have a pressure switch in the pump, so suggest air leak would be first to look for.

The rear diff lock should come on solid for a couple of seconds when you start (some for of system check) however I never seen mine blinking... Did u use the factory wiring loom and ECU in the end ?

Mine enagages immediately the pressure has built up (prob about 4-5 seconds) so 10 secs does sound too long. Remember it will not lock over about 10km/hrs using the ECU.