Your completely right about the torque..... but it's not just the torque alone, it's where the torque is delivered.... high low end torque is what's needed There are a lot of petrol engines with really impressive torque figures, until you see where they come in at.. 4000 rpm +... no good for towing, need max torque below 2000 rpm to be any good And while I do realise that Torque and Horse Power don't necessary go hand in hand, I have yet to come across a high power engine that didn't have a reasonable torque curve...

Got a feeling that the original idea of a Cummings BT6 and mechanical pump might be the best option... it just throws up some pain with the gearbox issues.... a 6 speed ZF would be the way to go but then its a pain to attach a transfer box to it.. unless there is enough room to fit a totally remote transfer box then things would be easy  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

BT6 weighs over half a tonne, an OM606 is far more sensible approach.

Agreed. That was the engine which took Otto to almost every country in the world.

I've seen it done too, and there's a conversion kit available which will fit 4 or 5 speed manual RR boxes, or even the 4 speed auto.

http://www.smt.nu/range-rover-mercedes-benz-300ddt6-cyl.php

manual D3 mapped for torque?

Needs mapping as they haven't got enough pull in standard guide. With a manual box you should do away with destroying gearboxes. There is nothing that can't be fixed with a hammer😜😜
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Now it's funny that you should talk about D3 manuals eating clutches.. that was the experience that a bog company I knew found out...

But I have just herd from an old colleague and he's just brought a D3 manual and is towing 3 tons + on a daily basis.... When I said about the clutch problems, he replied that for heavy loads he started in low range and knocked it into second gear high when he'd got to low 4 flat out.. apparently it will do this as it only requires neutral and the clutch to change

Wish the bloody Merc would do the same but that requires the foot brake to change  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

I tow our digger on a flatbed which is 3.5 tonnes all up, and it's the same with the D4. Start in low range if you have a slight slope it's what the manual says too.

Then when i shift up to 2/3rd I put it into high range once it's rolling. The car will switch range at any speed so long as it's in neutral.

You can do that in the FF too btw.

That said I have had 2 new clutches in it, but that is more to do with DMF and xy sensor issues than the clutch itself. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

also dont forget what ever you get you will have to have a tacho fitted to the tow car. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
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2021 Discovery 5 D300 MHEV commercial

How the are you doing the low to high in a ffrr, mine wont select gear without the brakes being on  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

You only need your brakes on under 10ish MPH
Above that speed it will allow you in and out of N D only

Low range - get the car rolling. Into neutral, change low to high, back in D and away you go. They all do it AFAIK

Im also in favour of a D3/4 manual... Great tow cars and NO crappy auto box to constantly worry you

My wife currently has a D4 Manual and i have a D3 Manual which i really ought to get round to selling! If you want to try one? Your welcome to pop in

Well I've been doing a bit of digging on the wonder web with regards to fitting a Mercedes OM606 engine in to a Classic, and giving it a little boost The engine can be boosted up to around 450 - 500 Nm @ 2000 Rpm for under a grand.... not an ecu with in a mile of it

An adaptor kit to a 5 speed manual box is under £600 + shipping from Sweden, so it's all looking rather promising....

I wonder if it's possible to fit an overdrive to the 5 speed box That would allow me fit higher ratio diffs and still get some economy...... I could have a tow range and a cruising range.... Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

yep just like that in the FF, get rolling in Low, knock it into neutral, then into high, then back into D.

"CHANGING FROM LOW TO HIGH
RANGE
With the vehicle travelling no faster than 60 km/h (38 mph), select N. Press the transmission switch (1) and release it.
Indication of the range change status is the same as for the stationary method.
Now select D or S."

from the 2010 manual.

you can even do it the other way


RANGE CHANGING ON THE MOVE
The recommended method of changing range is with the vehicle stationary. For experienced off-road drivers, a range change on-the-move can be accomplished, as detailed below.
Hi to Lo change:
1. With the vehicle slowing down, and travelling between 40 km/h (24mph) and 3 km/h (2 mph), select N.
2. Press the transmission switch (2) and release it.
3. Wait for the range change to be completed (this may take several seconds). Once complete, select D or S. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

DeRanged Rover wrote:

We run a Classic for our off-roading charity runs in Kenya and a lot of the folks out there have replaced the std 3.5/3.9efi with a Lexus LS400 V8 1UZ engine. Apparently its a relatively easy job and it gives you bags of low end torque which is what I presume you need? The 1UZ is a 2WD but will run with the Landrover gearbox so you get 4WD - if I recall you need a motec thingybobby to get it to match.

Or there is the 2UZ engine which used to go on the older Toyota Amazons - again bullet proof and you get the 4Wd gearbox that comes with.

If you'd like, I can speak to the peeps back home and see if they have install pics/guides?

C

chex, I have no idea who does these conversions , but if you go back to page 3 of this thread and scroll down to DeRanged Rover's post there is a "pm" button at the bottom of his post... you'll be able to ask him direct

And now back to the oil burner

I might have a bit of a problem... and with the build as well The conversion kit from Sweden comes with a flywheel adaptor.... this rather concerns me as it will mean an extra set of bolts holding the Range Rover flywheel to the engine..... fine for standard 330 Nm engines, the worry is I'm proposing a 500 Nm engine... could be tears

I could stick with the Mercedes flywheel, use a solid Merc flywheel and a hybrid clutch.. made from Hyundi and Merc bits and still use an LT77 gearbox... but then there is the question will the LT77 like 500Nm's of torque

Or I could forget the conversion kit and fit a Mercedes gearbox, that immediately gives me 6 speed options, but what to do about the transfer box?

Oh and I did wonder if there was an overdrive unit for the LT77 gearbox... there is Some cleaver chaps in Canada have noshed one up http://roamerdrive.com/ds_overdrive.html But it's rather expensive once Britparts have gotten hold of it So fitting a 6 speed ZF from a Merc would save me an extra 1.5K  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!