leolito wrote:

Well, yes and no, you have also deteriorating further hand and block which could be reconditioned and saved for another engine in the future. Do not know the policy of V8D (still pondering on how I will get my engine done and how), but from a mechanical perspective it would be a pity to totally ruin what left.
Sorry, I am a romantic :-)

If you expect to use the car these 6 months, maybe not as "intensive" use as originally planned, Richard's idea is not bad at all. And will save you some money on the trailer trip to V8D!

I'm not planning on using the car at all except for the 125 mile journey to V8 Developments.

Then I would risk it.
But I would talk with them beforehand, don't know if they take your engine as core or what, just to make sure there are no ... surprises or misunderstandings.

if you are going to drive it make sure that the heat from the opening is not going to catch fire or melt anything , even disconnect the plug lead so as to reduce the noise and damage that may occur , just an FYI.

Changed the pollen filters on the P38. Something I’ve been doing bi- annually since I’ve owned P38s.
Often overlooked when servicing these vehicles. After two years these were minging….
Worth doing me thinks.

Gearbox off, jeez, is it heavy or what and despite it being strapped to a transmission jack adapter on a trolley jack, it still used gravity for the last 6 inches of downward motion! Decided that with the transfer case attached we, that is me and a recently retired Land Rover workshop manager, could barely move it so removed that to make it slightly more manageable. New rear main oil seal fitted, spacer behind the flex plate changed for the thinner one needed to take account of the larger torque converter on the 4HP24, and fitted an Ashcroft Transmissions heavy duty flex plate. Figured that it will be easier (as opposed to virtually impossible) to fit the replacement gearbox and refit the transfer case once it is in place. I've got a bracket I made up years ago that bolts to the transfer case and fits into the trolley jack so it is at least held at the correct angle, so, in theory at least, that should be relatively straightforward. With two of us under the car, two trolley jacks, one with the adapter on it, a bottle jack and a ratchet strap to hold it steady on the main jack, lifted it back into place. Took a bit of wiggling to get it to slot into place but it went in and the bellhousing bolts were whacked in with the rattle gun Instead of two clicks a time on the ratchet. At which point, our respective better half's told us to call it a day if we wanted any dinner.

So, tomorrow is refit the transfer case and connect everything else up. The odd thing is that with the old gearbox out, it seems to turn smoothly with no noise although thinking about it, it is in neutral so maybe it only clatters when it tries to drive. The fluid is spotless, not at all cloudy, burnt looking or with any metallic shaving in it either.

so today's lesson is to remove the transfer case first and then the gearbox due to the absolute weight of the units.

I ‘learned’ that lesson some years ago. I took one look at the size of the gearbox/transfer box and it’s weight and decided that removal of this was one job I couldn’t do at home on my own without a proper lift. It’s about the only job I get the professionals to do (apart from painting that is). I have total respect for those that do take this on though.

I've had the transfer case off before when I put a new chain in it and even that on its own was awkward, a combination of the weight and the fact it hangs down at a strange angle. Two of us did it then with the car on a ramp but we didn't remove the exhaust so had to manoeuvre it over the exhaust cross pipe which made it more difficult. Today we are going to put it back before the exhaust and main crossmember goes back on. I'll report back later......

Being a key holder at work has its advantages especially if the weather is looking a bit suspect

So once overtime was finished saturday morning at 12.30 and all the other lads had gone home.

i pulled the old girl inside for a much needed seeing to.

oil changed,

new spark plugs opting for the NGK, i found the ones removed where bosch. I need a new set of leads as the originals are seeming very tired

usual air filters and pollen filters. The plenum filter is missing but i do have a replacement. But need more homework before i attempt that. Not as easy at the skinny version that was on the D2

Front Brake pads and then dropped the diff oils and topped them back up.

Not bad for a Saturday afternoon. Sods law the weather didn't turn to rain as it was meant to. But it was nicer being inside with a bit more space to work in

I had painful experience last year trying to swap out my transfer box for a new one. It is on the cards to have another go at it this year after I tick off a few more jobs round the house. I need to psyche myself up first.

Some of you may recall I got a local garage to do the heavy work. However the job went pear shaped. Horrible grinding noises from the new box. They ended up putting the old box back in to get me going. Cost a bloody fortune in labour. Charged 11 hours.

With hindsight I think it must have been my fault. I had replaced the epicyclic gears and I had also had the case apart. Something must have been dislodged inside. I need to have another look see and test it properly before refitting it. How? I don't know. Maybe spin it using an impact wrench on the drive shaft?

The know the garage never disturbed the gearbox when replacing the transfer box but they obviously have a car lift and a gearbox jack.

Richard: Once the propshaft, exhaust and cross member are off, what causes the box to hang down? Is it the weight flexing the engine mounts? I can't picture what the problem is. Won't it just slide straight back? Maybe support the gearbox separately?
You can tell I don't know what I am talking about as I haven't done it.

I have bought a platform lift and I like the idea of making a cradle for it to hold the box. A picture of yours to show the angle would be helpful.

I can rope someone in to help (haven't told them yet). I know it weighs 75Kg.

An update and to answer some of Dave's questions. It's in and it works, sort of..... Noticed the difference between the 4HP22 and 4HP24, the actual gearbox section of the 24 is 15mm longer but the tail housing is 15mm shorter so the overall length is the same. However, that means that while the overall length of the box is the same, the tail shaft sticks out 20mm beyond the face that the transfer case bolts to rather than the 5mm on the 22. After a bit of head scratching and measuring, realising that as the transfer boxes are identical and interchangeable, the only difference would be how far into the splines in the transfer box input shaft that the output shaft of the gearbox slides into. Measured the splines and found that they are easily deep enough to take the extra length. So as well as the other differences, the length of the splined connection between the two is greater on the 24 which, presumably gives it more strength there too.

So, after a bit of a struggle, the transfer case went back in and was bolted up to the gearbox. The main problem we had with that was supporting everything. With a large, 20 ton (overkill I know but it was given to me by a truck driver years ago and it's nice and big), bottle jack under the end of the gearbox where the mounting plate would go and the transfer case on the bracket sitting on the trolley jack, the bottle jack wouldn't allow the trolley jack to get close enough. Not wanting to support the weight of the gearbox on its sump and risk denting it, Bolted a length of steel angle to a spurious tapped hole in the side of the gearbox casting to take the weight. The other problem was getting the transfer box on the trolley jack under the car. I'd put my EAS High calibration blocks in the bumpstops so the suspension wouldn't drop and jacked the front wheels up until I could get ramps under the front wheels. The front wheels were then strapped to the ramps with the same ratchet straps used to secure cars to a trailer so it couldn't roll off.

But, it still wasn't quite high enough to get the jack with the case on it under the car. So it was Nanocom to the rescue. Plug it in, go to EAS, turn the compressor on and run that for a couple of minutes, then open the front and inlet valves so the front rose up, do the same at the back and we had at least another 3 inches of clearance. Anyway, transfer case in, and realised it would be easier to bolt up the front propshaft before the crossmember went in as access is easier. I know a lot of people have a problem getting a socket onto the propshaft bolts but I decided to replace the original hex head bolts with Allen headed bolts and had bought ones of the correct size and thread (3/8 UNF) along with new Nyloc nuts. That way all four can be done up without having to rotate the propshaft. Then it was time to refit the exhaust and crossmember. The exhaust was simple enough to put into place but the crossmember put up a fight. I'd had to use a crowbar to get it out and it needed a club hammer to get it back in, gearbox mounts (new ones) fitted and bolted up and we could finally remove all jacks from under the car, Exhaust bolted up properly, rear prop in, with more new nuts, prop guard on, connect the oil cooler and dipstick pipes, connect the wiring plugs, fit and calibrate the XYZ switch, poke the handbrake cable back up through it's hole in the floor and it was time for some fluid. At this point Dina came outside and asked how we were getting on, so I gave her a stepladder, a small funnel and two 5 litre cans of nice new Castrol ATF (at around half the price from Opie Oils than Eurocarparts own brand stuff). At one point she poured it in faster than the funnel could cope with so with ATF down the side of the engine and one exhaust manifold I knew it was going to smoke and smell a bit once it was started.....

Finally the time came to start the engine and see what happened. The inevitable cloud of smoke from the ATF all over the exhaust manifold and lots of greasy handprints on the exhaust but other than that, all seemed fine. The 4HP24 holds 11 litres from empty but there must have been a litre in there as with 10 litres, once running and checked, the level was smack in the middle of the min and max marks on the dipstick. Although the dash was showing Gearbox Fault and not displaying the selected gear in the message centre. Not the XYZ switch as the LED next to the gearlever was displaying correctly. Checked the fault code and it was giving an Engine Torque Fault, cleared the code, ignition off then back on again and the selected gear display was back and no Gearbox Fault. Started the engine and after it had run for around 20 seconds, the fault comes back. OK, but does it work or is it in limp mode? The answer is, it works, all gears engage, torque converter lockup happens and kickdown works but the changes, particularly down changes are harsh.

Checked in RAVE and it lists a fault of Engine Torque signal out of range with the affect being harsh gearchanges but no limp home mode. So that is what I have. A torque signal is sent from the engine ECU to the gearbox ECU. Thinking that maybe we had damaged the wiring (even though it is all in a protective flexible conduit) when putting the gearbox or transfer case back in, measured for continuity between the two ECUs. No problem. Then checked for a 12V PWM signal from the engine ECU and my cheapo Chinese graphical meter showed a waveform although it appeared to be showing a much lower level. Being fortunate in having another car, the Ascot, sitting there, checked that and found a completely different waveform and at a higher level too. Checked the two gearbox ECUs and found they are different (mine is AMR5493 marked 4.0 while the Ascot has an AMR5496 marked 4.6), so pulled the ECU out of the Ascot, tried that and this is where things start to get really weird.

With my original one, if I clear the fault then read the data, I get an engine power reading of around 45 at idle rising as the engine is revved, a battery voltage of 10.6V (?) and the gearbox mode as Economy (the ECU supports Normal, Economy and Sport modes although the P38 only uses Economy and Sport). After the engine has run for around 20 seconds, the power reading goes to 236, the gearbox mode goes to Normal, the dash beeps, Gearbox Fault comes up and the gear indicator goes out. In this state I get the harsh gearchanges. On the Ascot, with a 4.6 engine and 4HP24 gearbox, I get power of 52, again rising with revs, 13.8V battery voltage and gearbox mode of Economy. With the Ascot ECU on my car, I get power of 45, 13.8V and Economy mode for the first 20 seconds then the power reading changes to 236 but the gearbox mode stays at Economy, no Gearbox Fault and gear display stays on the dash. Driving it like that, it drives perfectly with super smooth gearchanges both up and down the box, kickdown works and so does Sport mode. Brilliant I think, cracked it but as soon as I exit the displayed data on the Nanocom, the dash beeps, Gearbox Fault comes up and the gear indicator goes out.

So, the situation at the moment is that with the Ascot ECU in and the Nanocom connected and displaying the gearbox inputs, it works perfectly (even if the engine power figure seems odd). The Ascot is an earlier car (96 model, VIN TA337218 showing a build in mid 96) and having checked the data on the gearbox in it, it is a model 030 061. The gearbox I have fitted is an 030 064 so would be from a 98 car which should have an AMR5692 ECU. It might be that all I need do is fit the matching ECU but I'll give Dave at East Coast Range Rovers a call in the morning and see what he can suggest as he has swapped gearboxes in the past and they have been a simple plug and play job.

Anyway, to answer one of Dave3d's questions, once the propshaft, crossmember and exhaust are off, flex in the engine mounts will allow it to drop down but as the gearbox mounts are attached to the crossmember, it'll try to sit on the floor. That's why RAVE tells you at the beginning of the gearbox removal process to remove the upper fan cowling, so you don't break the fan as the front of the engine rises. On the diesel I don't think you need to remove the crossmember to get the exhaust front exhaust pipe off, so leave it in place (in fact, I'm not even sure if you would need to remove the exhaust downpipe as it is on one side and not both as on the V8 although it might make access easier). With the propshaft off, remove the U shaped shield that is there to stop the propshaft flailing around if a UJ breaks (not that one ever should if greased regularly). There's 6 bolts holding the transfer box to the gearbox and the top two are a bit of a pain to get to, multiple socket extensions and universal joints needed. The first time I took mine off, I had to resort to using an Irwin bolt extractor (https://www.amazon.co.uk/Irwin-Bolt-Grip-Remover-Expansion/dp/B000QW6K8I) to get a good bite on them. They are flanged head bolts so the actual hex isn't that deep. My transfer case bracket is a couple of lengths of angle iron that fits onto the lugs where the bolts go and was made up with the case in the car so the bottom of it is horizontal and a suitable size socket to fit into my trolley jack bolted and welded to the bottom of it. That fits onto the bottom of the case with a ratchet strap around it to hold it in place. If I was to make another, I'd make it so a couple of the bolts on the case can be taken out and used to bolt the bracket to it rigidly. That way the transfer case can be unbolted, the bloody annoying and a real pain to get to, breather pipe can be disconnected and it can be slid backwards. Once clear it can be lowered on the jack and pulled out from under the car. Refitting it is the reverse but a couple of long M10 bolts to fit into a couple of the bolt holes to use as guides for it to go back in are useful.

KCR wrote:

Hi Richard, sorry for Your gearbox :-( please give an update if the hp24 fits, as I am planning the same swap (the one from a 4.6 GEMS with a bigger torque converter). If it is plug & play (I guess the tranny ECU has to be swapped, too?) but if they are the same lengths and how the 4.0 feels with the bigger TC? Would be gr8!!!

The 4HP24 fits and is a direct swap as long as the spacer behind the flex plate is changed for the thinner one from the 4.6 so the flex plate is closer to the flywheel giving more space for the larger torque converter. Seeing them side by side, it is quite a bit larger too so I thought it might affect the feel of the engine as it is in effect giving it a heavier flywheel but it doesn't seem to, it seems to feel no different.

As noted above, it does appear that I need to change the ECU but whether that always applies or is unique to my car because it was built to police spec I've no idea. My old 4HP22 always seemed to change up sooner than I would have expected it to, and sooner than the 4HP24 in the Ascot too. That and the fact I'm seeing different waveforms between the two cars from the engine ECU would also suggest something odd.

Managed to bust the oil filler tube.

Looked for a new 'un over £100 for a plastic tube!! fook that.. £30 on evilbay later.

Changed the oil too

Gilbertd, I should remember (but can't) who swapped the BMW diesel into their P38... Would they be able to shed some light on your problem?

Lpgc wrote:

Gilbertd, I should remember (but can't) who swapped the BMW diesel into their P38... Would they be able to shed some light on your problem?

It's Sloth on here that has done that conversion.

Probably not but it gets curiouser and curiouser. Spoke to Dave this morning and he has never had to change a gearbox ECU when swapping a 4HP22 on a 4.0 litre with a 4HP24 from a 4.6 and has done it at least 30 times on different cars, both GEMS and Thor, with no problems. This makes perfect sense as the only thing that is different is the gearbox and while it has an electrical connection, there's no electronics in the box itself, just the solenoids and output shaft speed sensor which are the same no matter what gearbox is fitted. After telling him what I'd found, took a run over to him. Running it with the gearbox ECU from the Ascot in there and the Nanocom plugged in displaying the gearbox inputs, it ran and shifted perfectly. Change points are a touch higher than with the old box but I always thought it changed up a bit too soon anyway (and at lower revs than the Ascot too). We tried all 3 variants of GEMS 4.6 gearbox controllers and all act exactly the same. He was as puzzled as I am.

Connected my graphical meter to display the torque waveform from the engine ECU. It is supposed to output a 12V PWM signal that will vary with engine speed and load. With the ignition switched on but the engine not running, it shows a near perfect square wave of around 8V peak and wide ON pulses. At that point the Nano shows an engine power of around 15 (not bad for an engine that isn't even turning over!). Start the engine and the pulse widths reduce slightly and the Nano shows a power reading of 50 ish, rising with revs. After around 20 seconds of running the pulses change completely to a very narrow pulse but at a level of only 0.7V. It is when this change happens that the power reading on the Nano changes to 236. Tried it without the Nano connected and the pulses changed just the same but as soon as they do, Gearbox Fault pops up and the gear display goes out. So, we now know what is causing it but not why and both agree that it is an electrical fault rather than anything wrong with the gearbox itself. A swift Google for P38 Engine Torque Fail, came up with this thread which describes that exact same symptoms I have https://www.rangerovers.net/threads/nanocom-engine-torque-fault-on-1995-auto-4-6-gearbox.334994/. That seemed to suggest a misfire, which I don't have, would cause the torque figure to drop and trigger the fault although I don't have a torque figure that drops, I have one that rises? In theory that should simply make the gearbox ECU think I had booted it. Although the writer of that thread didn't check and see the disappearing pulses from the engine ECU though.

Having got back home, with a spare gearbox ECU identical to the one from the Ascot, which Dave gave me. I wondered if I had some sort of incompatibility between my plod spec engine ECU and the 4.6 gearbox ECU. So, with the Ascot gearbox ECU in the car I pulled the Ascot engine ECU out of it too. Using the Nano Security Learn feature, paired it with my BeCM. Monitored the Torque pulses from it and the same. Perfect PWM signal with ignition on, start the engine and after 20 seconds the pulses disappear. While the Ascot engine and gearbox ECU's work fine in the Ascot, they don't in mine. Tried my engine ECU in the Ascot and the pulses don't disappear and it behaves perfectly. Swapped everything back so the Ascot was back to as it was and my car was but with another gearbox ECU identical to the one from the Ascot. Time for a coffee.....

While drinking my coffee I had another read through the thread. It isn't until post #15 where the actual cause of the fault is found. A dodgy connection in one of the wires between engine ECU, gearbox and gearbox ECU. Then it started to become clearer. This wiring exits the car under the centre console and dangles down underneath before going to the gearbox and transfer case. As it had been shoved around quite a lot while the two big mechanical bits had been removed and refitted, it may well be that one of the wires has been damaged. I've had a quick look underneath and found a new looking cut in the outer sheath but opening it up and the wiring all appears fine. It's quite possible that the movement has either broken a wire or caused a bad connection in one the the plugs under the centre console. So at the moment the console is partway out and I'll continue in the morning......

Wow. I’m reading with interest. You’re very persistent Richard and thanks for keeping us informed on the way.

Persistence doesn't have anything to do with it, I need it back on the road and usable. Particularly as it now looks like I caused the problem so I need to fix it.....

As the NanoCom must be providing a secondary route for the errant wiring just install the NanoCom as a permanent ‘accessory’ - job jobbed ;-)

I refer to these jobs as a Magnus Magnusson - you’ve started so you’ll finish!

Definitely an I've started so I'll finish job and I'm happy to report that I've finally cracked it. Figured that it had to be a wiring problem and had found a new looking cut in the outer sheath under the car so rather than try to investigate it laying on my back underneath, decided to take the centre console out. Far easier said than done and the connectors for the loom are under the sound deadening, which is under the carpet under the centre console. Finally managed to get to them and they appeared fine so poked the loom out through the floor so it dangled under the car. Disconnected it from the transfer case so was able to pull the back of the loom out from under the car and at least see it in daylight. Pulled the sheathing back and found one wire had been damaged, the insulation was cut but the conductor was fine. Insulated that and put it all back. On the offchance I had disturbed something, tried the car and still had the Gearbox Fault.

Working forward, I unplugged and checked all the connections to the gearbox itself, nothing wrong there either. All that left was the horrible 6 way Supaseal connector that hangs down behind the LH cylinder head (the one that always gets in the way when trying to take the LH cylinder head off). That looked fine from both above and underneath but decided to unplug it to have a better look. Figured it would probably be easier to unplug it from underneath, got hold of it and as soon as I moved it, this happened.......

Two wires just fell out. Now I may have caught it with the bracket on the gearbox dipstick tube when I'd taken that out or it may be that they were broken anyway and moving the loom while changing the gearbox had allowed the wires to move out enough that they were no longer making contact with the terminal I have no idea. All I know is that the wires all appeared connected and pushed into the plug when I initially looked at it but they came out as soon as I touched it. Unplugged it, dropped it down so it was hanging under the car, found a suitable piece of stranded multicore cable and soldered that to the wires after cutting the plug off. Passed the cable up the bulkhead, snipped the wires from the socket and soldered them too. Each joint was insulated with glue lined heat shrink, then all taped up at both ends too. Started the car and everything was fine, no more Gearbox Fault, all I had to do then was reassemble the centre console. Maybe I should have started at the front.....

Anyway, I can report that the car now drives perfectly. Gearchanges are so smooth they can't be felt or heard, all you can hear is the revs changing. So while it may have taken 3 days longer than originally expected, it's finally done. It's definitely one to bear in mind when that plug has to be disconnected when a cylinder head is removed. No point doing the head gaskets only to find you end up with a gearbox fault instead.