P38A Center diff lock issue

[jamesmartin]

May be Borg Warners advertised their transfer box like this, but in fact it isn't true and enough to make a cat laugh, that for person on framed 4x4 with axles will be better, to loose control of center differential - I already mentioned G-classe, which was more expensive and luxury than RR in 1990s, and still do it now - there are all three diff locks in all versions (Front, rear, center), and nobody said "Bitte, install viscous coupling, it's too hard for me to control diff lock". At least, they should have given the buyer a choice - like on Grand Cherokee, which had three transfer box - part time, normal 4WD and stripped down 4WD with same viscous coupling on p38 (All jeep owners don't like it, of course)

PS I don't want to buy Disco, Defender, G-classe or something else, I like p38 - but I want to fix mistakes of factory, to make it better.
PPS The button for diff lock isn't problem - I'm going to take original low gear button from P38 with manual gearbox - it's original and there is a picture of gear with letter "L" on it, the best variant of diff lock button, only P38 guru will understand, that it's not original diff lock system


Yes, I know, that traction is part of ABS and not connected to viscous coupling, I just told, that this system is useless, than the car slips for long time, unlike diff locks. The traction failure on that 2001 P38 wasn't because of mechanical problem, it was a result of long time slip.

it is a better box,its just you can select lock up,,its smoother quieter and doesnt have the back lash the the lt 230 does ,until its worn out
no land rovers are sold with 3 difflocks,so traction control is just an added bonus that has uses and limits

 

[Grrrrrr]

The viscous is, supposedly, progressive, try turning a jacked front wheel by hand, there is a small amount of lock between front and back at all times, until the batard fails and seizes completely. It's the differential rotational speed between front and rear drive lines that causes lock up, so no need to "boot it" as you put it, all it needs is one end to lose traction.

Theoretically, maybe but not what I've found in practice. When the TC kicks in you lose momentum as well which doesn't help on the slippy stuff. You have to be way more aggressive with the throttle compared to the Defender.

 

[jamesmartin]

Yes, you cannot beat the 3 diff locks. The viscous coupling requires different driving as it needs to lock up. That means booting the damn thing to get it to lock up. That will work the brakes hard if the TC kicks in though so understand where you are coming from. It certainly burns the brake fluid if you do a lot of it so you need a complete flush out of the fluid if you do it a lot.

The Disco 2 still had centre diff locks, didn't they? That'd be my starting point.

a few did,early ones had the box internals but no operating mechanism in the cab,then it was removed completely then an option

 

[jamesmartin]

Theoretically, maybe but not what I've found in practice. When the TC kicks in you lose momentum as well which doesn't help on the slippy stuff. You have to be way more aggressive with the throttle compared to the Defender.

i find you just need to raise the revs slightly to counter the tc braking effect

 

[300bhp/ton]

Theoretically, maybe but not what I've found in practice. When the TC kicks in you lose momentum as well which doesn't help on the slippy stuff. You have to be way more aggressive with the throttle compared to the Defender.

You do need to drive differently to make the TCS work. But tbh no differently than you would with a Td5 Defender with TCS.

It’s quite funny watching people with Td5’s. A lot of the time they just get to the point when the TCS kicks in, then they back off the throttle. Seen it so many times at trials events.

The trick I’ve found is to be smooth on the throttle. When the TCS kicks in, stay in the throttle a bit, or gently roll into it a little more. Should be no need to floor it.

This is really all about how the TCS works. With open diffs the diff will be splitting the torque 50:50 between each wheel. But when one wheel looses traction or lifts off the ground, all the power will be sent to it and it will spin and not move the opposite wheel. A bit more momentum, different line or steering input can help avoid this. What the TCS does is brake the spinning wheel and produce load on it. By generating load on the spinning wheel, it will force the opposite wheel to rotate.

So the trick is to keep the wheel spinning. Backing off will not generate enough load or may even stop the TCS engaging at all. Remeber the opposite wheel will rotate slower while one is spinning. If you are going slow such as tickover speeds, just gently roll into the throttle to keep the wheel spinning and the TCS working.

Flooring it may sometimes be the answer. But generally it will make it harder for the TCS and force the brakes to work harder. And may end up braking traction on the wheels still in contact with the ground.

This is a Tdci Defender. But the principle is the same and I’ve driven my p38 round here.

Skip to 43 sec in. See how just rolling into the throttle activated the TCS. No flooring it.

 

[300bhp/ton]

The Disco 2 still had centre diff locks, didn't they? That'd be my starting point.

Most D2’s didn’t have a the diff lock. Some earl ones have the mechanism and are just missing the upper linkage. Then for a period the mechanism was removed. Then a full centre diff lock offer as an option.

D2 uses different chassis, axle casings and radius arms to a p38. So swapping in an LT230 from one to a p38 probably isn’t just a matter of bolting it in.

Although with a bit of thought and fab work is probably the easiest way to fit an LT230 to a p38.

 

[wammers]

Think of the P38 as a road car with off road capability and not as an off road car with road capability and all will become clear.

 

[Bexer]

it is a better box,its just you can select lock up,,its smoother quieter and doesnt have the back lash the the lt 230 does ,until its worn out
no land rovers are sold with 3 difflocks,so traction control is just an added bonus that has uses and limits

No. May be LT230 isn't best transfer box ever made, but it's even much more better than borg warner. If they don't like back lash, they could buy normal transfer box from normal factory. I saw a list of all Borg Warners transfer boxes, they produced only weak trancfer boxes for on-road use.

It's bad and nothing to proud of in here, if P38 had all 3 diff locks in stock... would be best 4x4 ever made. But instead of this, viscous coupling, like on modern parquet SUVs

a few did,early ones had the box internals but no operating mechanism in the cab,then it was removed completely then an option

It's all about BMW era, it wasn't Land Rover (Land Rover ended in 1994, good that p38's before restyle wasn't corrupted by BMW), it was a way for german car. Also BMW can't into normal off-road SUV.

i find you just need to raise the revs slightly to counter the tc braking effect

Very convenient off road - remember, than traction tries to reduce power on wheels, remember, that axles should slip, to engage viscous coupling, remember the phone of nearest tractor... It's not offroading to the interesting place without people and civilization, it's picnic in the garden on Dacia Duster. And it't not suitable for car, with frame, axles and stock winch.

Most D2’s didn’t have a the diff lock. Some earl ones have the mechanism and are just missing the upper linkage. Then for a period the mechanism was removed. Then a full centre diff lock offer as an option.

D2 uses different chassis, axle casings and radius arms to a p38. So swapping in an LT230 from one to a p38 probably isn’t just a matter of bolting it in.

Although with a bit of thought and fab work is probably the easiest way to fit an LT230 to a p38.

I really can't understand, why they mirrored axles on P38, it's strange.

Yes, I also think, that LT230 swap is a better way. I'm going to buy LT230 and see, that I can do with it - may be I'll produce new case for it, suitable for P38

Think of the P38 as a road car with off road capability and not as an off road car with road capability and all will become clear.

Road car with front axle and stock winch? Wrong position, I don't like parquet SUV's - and that's good, that P38 isn't one of them. I bought it, because it's mostly normal offroad 4x4, and I thought how to uninstall VC from the first day with p38 (And a little time before deal)

 

[jamesmartin]

No. May be LT230 isn't best transfer box ever made, but it's even much more better than borg warner. If they don't like back lash, they could buy normal transfer box from normal factory. I saw a list of all Borg Warners transfer boxes, they produced only weak trancfer boxes for on-road use.

It's bad and nothing to proud of in here, if P38 had all 3 diff locks in stock... would be best 4x4 ever made. But instead of this, viscous coupling, like on modern parquet SUVs



It's all about BMW era, it wasn't Land Rover (Land Rover ended in 1994, good that p38's before restyle wasn't corrupted by BMW), it was a way for german car. Also BMW can't into normal off-road SUV.



Very convenient off road - remember, than traction tries to reduce power on wheels, remember, that axles should slip, to engage viscous coupling, remember the phone of nearest tractor... It's not offroading to the interesting place without people and civilization, it's picnic in the garden on Dacia Duster. And it't not suitable for car, with frame, axles and stock winch.



I really can't understand, why they mirrored axles on P38, it's strange.

Yes, I also think, that LT230 swap is a better way. I'm going to buy LT230 and see, that I can do with it - may be I'll produce new case for it, suitable for P38



Road car with front axle and stock winch? Wrong position, I don't like parquet SUV's - and that's good, that P38 isn't one of them. I bought it, because it's mostly normal offroad 4x4, and I thought how to uninstall VC from the first day with p38 (And a little time before deal)

no lr has 3 diff locks and only a tiny minority would need them, the ftc1564 classic borg warner was as strong as an lt230 they shared the same center diff gears,the p38 model much stronger,the fact you prefer a lever to select lock is no reason to rubbish the whole

 

[300bhp/ton]

As an example. Many competition vehciles like this use the Borg Warner transfer box through choice.

And this p38 still has a Borg Warner and drove the same places Defenders did.

 

[Bexer]

no lr has 3 diff locks and only a tiny minority would need them, the ftc1564 classic borg warner was as strong as an lt230 they shared the same center diff gears,the p38 model much stronger,the fact you prefer a lever to select lock is no reason to rubbish the whole

Of course I prefer lever with mechanical diff lock and this is a thread about it.

As an example. Many competition vehciles like this use the Borg Warner transfer box through choice.

And this p38 still has a Borg Warner and drove the same places Defenders did.

May be it's p38 with seized\welded VC - if you drive only\primarily offroad, you don't need differential

 

[wammers]

Of course I prefer lever with mechanical diff lock and this is a thread about it.



May be it's p38 with seized\welded VC - if you drive only\primarily offroad, you don't need differential

Hope you have a good supply of spicers and props. Not to mention the occasional diff.

 

[Grrrrrr]

May be it's p38 with seized\welded VC - if you drive only\primarily offroad, you don't need differential

I do think a limited slip diff combined with the 4W TC could make quite a big difference. Again, I think Ashcroft might do one but no idea what the price would be. Together with Airlockers I think it'd be a very capable vehicle for most people's use.

As you say though, if you prefer levers (and I can see the attraction as I miss the diff locks off the old Defender) and have the time/cash then we'll watch with interest.

 

[funrover]

I've owned many Range Rovers and the Late Classics and the P38 are by far the best off road..

My current P38 i've had buried up to the bumpers in **** and its pulled itself out without much issue.

Same for the late classics..

My Ancient classics coped OK but were no where near the ones with the Borg Warner VC box.

 

[Datatek]

I'm no off road expert, but my Hyundai Galloper climbed the grass slope in the wet from my garage with no problem, 4WD, no centre diff LSD rear diff. With the P38, there is a hell of a lot of clacking from the 4 wheel TC and it slip slides all over the place to such an extent that it's parked outside on the hard standing in winter these days. So to me, the TC & viscous are no substitute for locked diffs.

 

[jamesmartin]

I'm no off road expert, but my Hyundai Galloper climbed the grass slope in the wet from my garage with no problem, 4WD, no centre diff LSD rear diff. With the P38, there is a hell of a lot of clacking from the 4 wheel TC and it slip slides all over the place to such an extent that it's parked outside on the hard standing in winter these days. So to me, the TC & viscous are no substitute for locked diffs.

nothings going to beat axle lockers,but since lrs dont come with them tc is a step up from std,and ive found mine very useful at times

 

[eightinavee]

Bexer, ever tried pushing a P38 by hand - heavy isn't it,even in a straight line. Now try turning the steering wheel to full lock - can you push it now ? I don't think so... If you can your VC is bu##ered. The VC allows only a very limited amount of slip when working properly. Read the test procedure in the workshop manual,it will help you understand how the car works.
Fitting air lockers or LSD's front and rear would be an upgrade, removing the BW would not. Simple.