94 Range Rover Classic Diesel Conversion using Mercedes 1987 300SDL 300tdi & Tranny

JohnnyBGood

New member
94 Range Rover Classic Diesel Conversion using Mercedes 1987 300SDL 300tdi & Tranny

Hello Everyone, first post, so go easy on me lol...

I know the topic of Diesel conversions is one that has seen its day and has had its fair share of posts, but I'm gonna throw my question into the mix... Before I do, I'll say that I had considered this idea for a couple of years now and shelved it about a year ago after reading all of the posts back then. Now it is a year later and I have started researching the idea again and low and behold the posts I pull up are all the same ones that were around a year ago! So time for some new blood...

I have a 3.9L 1994 Range Rover Classic LWB that I'd like to do a swap on. I love the truck and used to drive it often up until about three months ago when I noticed what sounded like a loose exhaust shroud or something minor like that rattling from the back of the engine compartment. When I got under there and poked around, what I found was not a loose shroud, but a bolt or something loose in the bell housing. I'm guessing it may be a bolt associated with the TC, but not sure at this point. So, realizing that it won't be as simple as I thought and will probably require separating the tranny from the block, I started thinking about doing a diesel conversion again.

I have access to a really nice old 1987 Mercedes 300SDL (300tdi and 722.321 transmission) that runs great and shifted smooth before it was decommissioned due to an accident to the right front portion that affected the front axle of the car but didn't affect touch the drive train. It still runs and shifts, but can't be driven anymore. This would be my donor car.

So here's my question: Can I swap the drive train (motor and tranny together) from the 300SDL and put in my Rover without too huge of a headache or expense? I remember reading a post from someone else who was going to do the same thing and custom fabricate a shortened drive shaft to the transfer case. I'm not sure how that project turned out in the end, but it sounded to me like a great idea.

I'd rather go this route than to go through the gyrations of trying to mate up the 300tdi to the ZF tranny and then have to worry about shift points etc. I know some may say off the bat may say that it will be under powered and that the MB tranny isn't strong enough to move the Rover well, but I would counter that the 300SDL isn't exactly a featherweight itself.

As a matter of fact, the curb weight for the 300SDL is 3836 lbs. and my Rover is 4574 lbs., a difference of 738 lbs. The Gross weight on the MB is 4872 lbs. compared to the gross weight on the Rover of 6019 lbs. My rover is a weekend car that I would never load up to the gross weight or try to pull a trailer with. I have my wife's suburban for that stuff. I don't mind going low and slow with it either because I never drive the rover for anything that would be considered mission critical or need lightning fast arrival times.

I'd rather swap both together Instead of splitting the tranny off only to go through all of the headache of trying to adapt it to the ZF or finding a 5 speed manual Rover tranny and have to install the pedals etc...

So, long story long, is this a do-able idea? Is it a good idea? Is it a bad idea? Has anybody out there tried this with any success or failure?

Thanks in advance for any advice...
 
Last edited:

roverandom

Adventurer
Long answer short, no. It's not a good idea.

Custom power train swaps never make economical sense and always take way more time and effort than anticipated and have mixed results. Especially Diesel swaps.


Just wait a few more years and import a real Factory 300TDI/200TDI RRC.

Fix the Rover V8.


Or put a predictable Chev LS small block/4L80E under the hood. You will get the same kind of mileage without the problems of an anemic, obsolete old Merc Diesel.
 

JohnnyBGood

New member
Thanks for the quick reply roverandom,

I had read about using Chevy powerplants, but hadn't researched the details. Parts would be definitely be cheap and readily available. Can you expand on 'LS small block'? I could probably get that as a crate motor, but what is an example of a donor car/truck I'd be looking for to get the drive train from?
 

psykokid

Explorer
The other thing that you will run afoul of doing that swap is that your are swapping in an engine that is older than the year of manufacture for your truck. Federal EPA guidelines state:
installation of a light-duty engine into a different light-duty vehicle by any
person would be considered tampering unless the resulting vehicle is identical (with regard to all
emission related parts, engine design parameters, and engine calibrations) to a certified configuration of
the same or newer model year as the vehicle chassis

That last little bit is the kicker.. Now depending on where you live, they may not give a rats behind about the swap. Laws vary from state to state, out here in Kommiefornia the first time you went to get it smogged they would send you to the smog referee to have your installation checked out. And since your motor is older than the chassis there's no way it would fly unless you found some merc model that was sold at the same time as your RRC and you swapped it all over with the correct emissions junk for that engine model..

Other than the legality of it, what transfer case are you going to use that will mate up with the merc gearbox?
 

LR Max

Local Oaf
This is true. Really you should be installing a NEWER engine.

That said, I see you are in TX...the land of "magically fixing titles" so you've got that going for you.

Google Robert Davis conversion. I think he sells everything you need to bolt right up to a rover transmission.

As others have said, repairing what you have now will be a lot cheaper and easier.

The problem is everyone gets all hot and heavy on diesels. People install them then I hear issues with power. The V8 is ACTUALLY a lot better for US roads than the diesel. Sure the 300 TDI and merc engines are great for going 25 mph across some miserable road in some 3rd world country...but that ain't us.
 

XJLI

Adventurer
The problem is everyone gets all hot and heavy on diesels. People install them then I hear issues with power. The V8 is ACTUALLY a lot better for US roads than the diesel. Sure the 300 TDI and merc engines are great for going 25 mph across some miserable road in some 3rd world country...but that ain't us.

this x10000000. 6.0/4L80e in a RRC will be awesome. over 300hp and 20 mpg all day long.
 

David Harris

Expedition Leader
A guy here in the Chicago Land Rover Club put a Mercedes Turbo Diesel in his D1 mated to a Land Rover R380 manual 5 speed. To my knowledge it worked but he had problems with the durability of the flywheel/clutch setup he was using and took the motor out.
 

LR Max

Local Oaf
this x10000000. 6.0/4L80e in a RRC will be awesome. over 300hp and 20 mpg all day long.

The LQ4s and LQ9s are epic awesome.

That said, I'm seeing the benefit of the new Gen 4 trucks. My local shop is swapping a Gen 4 5.3 and 6 speed auto into a 110. When its done, I'll ask to go for a ride.

For me I'll do doing an engine swap but I'm doing a full drivetrain and suspension swap. Basically, it'll be a new truck and that is the mindset I'm going for. Gen 4 6.2 with 6 speed auto and atlas case should solve all the problems I've been having with my series 2.25 engine.
 

David Harris

Expedition Leader
I've considered various engine swaps for years, but when it comes down to it, having a Rover engine is part of being a Rover to me, for better or worse.
 

JohnnyBGood

New member
Donor 300TDI and Tranny vehicle.

Wow, I woke up to a treasure trove of replies, thank you all!

Well, the Merc I have access to was a great running and driving car, so although it being old, under powered and clanky, I know it is a solid runner. The history on this car is that it was a General in the Air Force (I'm in San Antonio TX, Military City USA) who passed away and whose adult daughter wrecked it. I would have all of the service records and original purchase docs from when it was brand new.

Alright... Now I wasn't as forthright as I could have been. I gave you all the description I gave my wife when trying to gain her approval for the purchase, "Honey, it only has minor damage, barely a scratch!". That being said, I know the car is solid all the way around. If it were newer, the insurance would have paid out to get it fixed. The car has just over 200k miles and all those diesel lovers (including me) would say that it isn't even broken in yet.

All that being said, I think the sound of a clanking diesel adds a little bit of cool factor to the truck. I don't know why, but to pull up to the convenience store, with the clankiness will turn some heads. I already get the occasional thumbs up when driving and have been stopped a couple of times to ask about the truck. I love my Rover...

My '94 has 223K miles on it's 3.9L so it's no spring chicken... My gut says it's getting a bit tired, just like I'm getting a bit tired of the crappy gas mileage. I think my motor was rebuilt at some point because I ******** you not it doesn't drip any oil on my driveway. Looking underneath, there is of course some oil visible, but not on my driveway. And yes, the crank case is filled to the proper level lol. I have not had to add any oil in between changes if that tells you anything. If it weren't for the rattling of the loose bolt, I would not even be considering this again.

So here's a question to you more experienced Rover mechanics, how difficult is it to pull the bell housing to see if a bolt falls out? I don't think there is anything else wrong with it because up to the point I parked it, it drove and shifted fine. No shaking or anything, only a loud clanking like a bolt being tossed about inside the housing. I have an engine hoist, but would have to get a transmission jack (which I had planned on doing anyways).

I am limited on time at the moment of me writing this, but I would like to read each posting a little more thoroughly to ask some questions.

Again, thanks everyone for your advice.


You know, hearing more about the Chevy conversions with the improved mileage and power to spare really intrigues me. I'd like to look into that more. My truck is a driver, not a restoration candidate in my opinion. I'll have to snap some pics to share. I'll post those soon.

Going back to the Chevy conversion, what is an example of a common vehicle I would use to source the parts from? I'm just trying to get a mental picture of it all.

With my original idea of the Merc engine and tranny, I was hoping to modify it to use all of the rest of the running gear (transfer box etc...) on the truck.

00f0f_e3uZgd12BO3_600x450.jpg
 
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XJLI

Adventurer
if it was my RRC, i'd grab a clean looking 5.3 from a junkyard, a NV4500, and the adapter to put the NV and LT230 together. i'd be upgrading axles soon after bc i'd be blowing them to bits.
 

LR Max

Local Oaf
For a Gen 3 Chevy engine, grab a 5.3 or 6.0 out of pretty much any chevy truck or SUV from 1999 to 2007. Grab the transmission too. I mean, you can go with a NV4500 but good luck finding one in a junkyard. You MIGHT find a factory 5 speed (NV3500, go with that since it'll come bolted up to the engine with all the required whatnots) but most likely it'll be the 4 speed auto. Good transmission. Adapters to the LT230 are available. Oh and grab a LS1 intake manifold. That drops the overall engine height significantly.

From 2007 to 2013 is the Gen 4 engines. They come with a mighty fine 6 speed auto. Once again, adapt it to the LT230. Plenty of info over on defender source about this.

Nice thing is that you can get the full wiring harness, computer, etc.

Install and then enjoy Awesome.
 

cosmic88

Observationalist
wheels on the bus go round and round....

You have an engine you like and know, you have a trans and a truck.

DO IT and have fun. make the swap after doing a bunch of research and asking those who have done it personally.
 

XJLI

Adventurer
For a Gen 3 Chevy engine, grab a 5.3 or 6.0 out of pretty much any chevy truck or SUV from 1999 to 2007. Grab the transmission too. I mean, you can go with a NV4500 but good luck finding one in a junkyard. You MIGHT find a factory 5 speed (NV3500, go with that since it'll come bolted up to the engine with all the required whatnots) but most likely it'll be the 4 speed auto. Good transmission. Adapters to the LT230 are available. Oh and grab a LS1 intake manifold. That drops the overall engine height significantly.

From 2007 to 2013 is the Gen 4 engines. They come with a mighty fine 6 speed auto. Once again, adapt it to the LT230. Plenty of info over on defender source about this.

Nice thing is that you can get the full wiring harness, computer, etc.

Install and then enjoy Awesome.

i read the 4L60 doesn't clear the front driveshaft w the LT230, and that the 4L80 does. Any truth to that? My D1 is in awesome shape and I'd hate to toss it when the motor goes. I can get a 5.3/4L60e for cheap.
 

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