Okay guys only just signed up to this forum but I'm sure I will be posting a lot! I own two 240d's! A very good condition '74 with an auto box, and I have recently procured a '75 240d which is a bit of a rotter and has been sat for around 13 years.

The '74 started off life as a taxi in Vienna and was imported to the UK in '79 and was restored in the early 90's. Sadly the engine has has it and I'm pretty sure has probably covered half a million miles. To top this off a coolant hose blew a couple of months ago and the car overheated caused the head gasket to go. I striped down the top end, checked the head mounting face with a clock and it was still good so no skimming needed (not that it should have warped being a cast iron block but thought I'd check anyway) replaced the valve stem seals, reset the valve clearances and then put the engine back together with the new headgasket. It ran for a little while but was still overheating, since I had already renewed most of the cooling system (new hoses, thermostat, etc) I have come to the conclusion that the head must be cracked or something else is wrong with it that I can't be bothered to fix at this time.

Anyway,

The '75 has a good engine (with a documented 157k on the clock and runs pretty good from what I can tell) so my plans are to swap out the engine from the '75 to my '74.

Only thing is the '74 is a auto box and the '75 is a manual. I want to use the auto box can anyone give me some pointers put the new engine in? Something about flywheels being different? Or the crank? Not too sure as I have never played about with gearbox's before, especially on a RWD car as I'm used to FWD golfs!

Anyone done this before?

Cheers!

Rory (P.S. I'm from the North Somerset in the UK if anyone is localish to me! Would be good to get to know people )

Why would you want to use the autotragic when you have a manual available?

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Some overall observations.

During this era many Mercedes crank and flywheels were balanced as a unit. I do not know if this is the case for this engine.

Flywheels for automatics and standards were different and one will not work with the other. The bolt pattern on the end of the cranks were also different but not in all cases. This is an area that you need to research carefully.

I would think that unless you just want an automatic you should transfer everything from the standard car into the automatic. This could be very involved, but in the long run the best solution. The pedal assembly will come right out of one car and go into the next, but you would also need to change driveshafts over and even the rear-ends. The radiators are also different as is the hole in the console.

But to tell you the truth all of this is much easier than it sounds. You can drop in the engine and standard transmission as a unit and then bolt in the other bits. Swapping the driveshaft is a one hour job and swapping the rear end takes a little less. Swapping the radiators out would take less than thirty minutes.

There is a crossmember the transmission bolts to and this would have to be adjusted to the rear transmission mount. That might take ten minutes as it only involves moving two bolts.

This would be my solution, but as long as you had both engines out you could check to see if the standard flywheel will bolt up to the automatic flywheel. If they do not bolt up perfect then they will not bolt up at all. There is no room to play with here; close is not good enough.

Good luck, and keep posting details here as you progress.

Of some importance.

This engine has no traditional flywheel. It uses a flexplate and a ring gear. The theory behind this is that the teeth on a flywheel see all the wear so this system allow for the owner to replace just the part (the ring gear) with the teeth on it and not the entire flywheel.

There is a part number for the automatic flexplate, 115-032-00-06-M22, but I cannot find a number for the standard transmission flexplate.

Just a heads-up to help you search for the correct parts if you need to.

Simple answer = Because I like the 3 speed auto! The car is more of a show car than a daily driver and I like the idea of just putting it in 'D' and that's it.

I can see the benefits of the manual and if it's easier I might as well just do that.

However I will pull the box and have ganders and look at if they will mount up.

Out of intrest if I was a to do a full manual conversion would I be able to swap to pedal box out of the manual (as it's a UK standard right hand drive) and swap it into my current auto (which is a left hand drive)? Anyone know?

Cheers guys!

I would be willing to bet it is a four speed automatic. At least my 1968 is a four speed and my 1987 is a four speed, so I assume that is pretty much the minimum number of forward gears in an MB automatic between those years.

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1968 220D, w115, /8, OM615, Automatic transmission.
My 1987 300TD wagon was sold and my 2003 W210 E320 wagon was totaled (sheds tear).

A number for "the standard transmission flexplate" is not to be found for a very good reason: There is no such thing!

The flywheel for the standard (i.e., manual) transmission is a ~28lb. cast steel piece bolted to the flange of the crankshaft. It has the starter ring gear shrink fitted to it.

The flywheel for the auto trans is a much lighter piece, less than 10lb., which also carries a shrink fitted ring gear. The bolts which attach it to the crankshaft also attach the triangular flex plate which in turn drives the torque convertor.

The crankshaft bolt patterns for both the manual trans flywheel, and the auto trans flywheel are the same. The thickness of the flange of the crankshaft MAY be different between the two engines. As a consequence, the position of the ring gear vis a vis the starter teeth must be determined by the method favored by the Brits : suck it and see.

Maybe you are correct then! The previous owner told me that it was a 3 speed, and after driving it for a while up to about 55/60mph I can confirm that it only has 3 forward gears maybe there is a problem with the box then.

I guess another reason to pull it out

Some of our transmissions (through design or poor adjustment) start in 2nd gear. There is an ongoing discussion as whether this was ever by design for U.S. based diesels. So if you experienced only 2 shifts, it may be that your transmission is out of adjustment.

Did the car run out of rpms at 60 mph? That would imply that maybe your highest gear is MIA. Normally, it is the 1st (lowest) gear which gets skipped, so people think they have a 3 speed, when it is actually four.

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1968 220D, w115, /8, OM615, Automatic transmission.
My 1987 300TD wagon was sold and my 2003 W210 E320 wagon was totaled (sheds tear).

I would love to check but that engine isn't going anywhere for now!

I would be willing to bet that it must have started in 2nd gear and motorway cruising the engine noise was not that loud (there is no RPM guage in the car).

I have no problem with the car pulling away in second as it seems to manage fine, but obviously a manual gearbox conversion is on the card now!

Just still trying to find out if the pedal box out of a RHD car can be swapped into a LHD, and also wondering where the clutch cylinder (master or slave) is on my manual doner car, hope it won't be too much hassle to change over.

Should be a good bit of fun anyway!

Ps. It has also crossed my mind that I could convert the whole car from a LHD to a RHD as I have every donor part I need in the form of my other car, does anyone know of this being done before? Il thinking that it shouldn't be that involved as LHD and RHD cars where made side by side in the factory but I could be wrong...