I recently converted my '83 300TD to a 4-speed. The results are most pleasing. Total cost was less than $900 ($600 for the donor car - a '79 240D) and took a week - not counting preparations. I never thought I would consider this car 'peppy'. I recommend this project to anyone who is fed-up with the original automatic or just wants to enjoy being in control again.
Leo, your documentary is great, I would like to have seen it before I srarted my project, but it is quite straight forward (95% bolt-up).
The only mods were to shorten the driveshaft and shift linkage about 4 inches and 'moving' the tranny mount bolt holes in less than an inch so the mount remanied straight across. The pedal set was a back twister.
All parts fit together just like they were made for each other. The trickest part for me was developing a technique for installing the clips on the ends of the shift linkage
After a few months, I am still learning how to shift smoothly with a very responsive (touchy) turbo throttle.
Enjoy, Jacob

I have replaced the back three shifter rod bushings/grommets. They don't give you much room to work. There appears to be much less room to work on the front ones.

Are the bushings the same at each end of the rods? The guys at the parts counter in the dealership can't seem to nail down the exact parts I need. I have two more like the ones I installed in the back and will attempt to install them in the front soon.

'82 300D Euro version with a four speed trans.

Both cars are looking good to go.

I just test drove the 300D. At first it was as slow off the line as a frozen dead dog, even my TD could kick it's a*s.

But, 3/4 CCW turn of the ALDA completely changed that! Now my TD can't touch it. It even barks the tires in the 1-2 on DRY asphalt!

It just needs some basics:
Valve lash
Valve timing (Woodruf key)
IP timing
Rebuilt/balanced injectors
Thermostat (Runs 100*-105*C all the time.)
Adjust the boost from 9.5-13psi
COMPLETE degreasing.
New glow plugs and GP timer/relay.

The only major work it needs:
Replace turbo bearings/rebuild the turbo (A little more than 1/16" up-down play)
Replace the waterpump.

I found this info in a 4x4 engine swap forum:


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physically, the 300D is a 240 with an extra cylinder. however, whiele the 4 is fairly eay to build as a balanced motor, the crank configuration of the 5 cylinder is inherantly un-balanced, and the flywheel assembly is used to damp out vibrations, ergo, 'no' a 240D flywheel will NOT work on a 300D. If you're completely set on the idea, what you can do is order a 300D manual flywheel out of europe or australia...according to the benz manuals I have, the recommended procedure for installing it is to 'remove crank, rods, and pistons, then have new flywheel and crank assembly dynamically balanced by a mahcine shop'. thats with a factory spec, brand new flywheel - just a hint on how critical the balance issue is on these engines. On the automatics, the fluid in the torque convertor actually functions as the balancer, similar to the aftermarket 'fluidampers' available for north american V8's.

Of the four 300D/manual conversions I've heard of using non 300 flywheels, not one is still running. I'd say it IS possible, if you're willing to spend a lot of time, and effort building a custom , dynamically balanced flywheel, but probably not worth the cost VS importing one.

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-ggg

Mine must be one of the "rare" ones according to them then, it's smooth running and has been since last year when I converted it with a 240D flywheel/tranny on 300D motor, like most of the conversions I've seen (which are ALL still running BTW - must be a real "pro" on that forum there )

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1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


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"If you don't know where you are going, any road will get you there". Lewis Carrol

LMK if you want to try my rebuilds (match balanced).

As far as the turbo bearings, LMK which turbo it is, I have another set of bearings for the Garrett, cheap.

May be down in Denver this week and could meet up, LMK how your time looks.

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1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


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"If you don't know where you are going, any road will get you there". Lewis Carrol

With my work (9am-5pm) and school (6pm-11pm) I dont have any time during the week and I'm busy this weekend (Parents in town) but I have no school all next week.

But, I have bad news. My boss won't sell me the 83 300D. He thinks we may fix it up and sell it for $4K He is still willing to sell me the 240D but I need to look someplace else for a donor/engine. The gray 81 300D we got at the same time is a total POS (Internal rattles, oil COVERED, lots of turbo play, and the wastegate boost line looks like it fell off long ago...).

So, I'm in the market for a good, strong OM617.95 engine. I'll talk with Hari first, he may be interested in my TD and he said he has extra engines.

Side note: Bruce (My Boss) has SOLD his 1985 300TD (CA emissions) for $7k I honestly feel sorry for that buyer, I'd never pay more than $4000 for it. He also said I should not ask less than $3500 for my TD.

After re-reading this entire thread, I would like to share some thoughts. The results of converting my beautiful 1983 300TDt (120k miles) were quite painless and very pleasing.
In no particular order:
The front wheels driven onto 10’ high ramps and then 10” blocks placed under the rear wheels. This allowed plenty of working space underneath and was very stable/safe.
My donor car was a 1979 240D [$600], also a W123, so the parts were made for each other. I took the parts off myself so as to learn how things were supposed to look when reinstalled. Keep track of all bolts removed!! I used the adaptor plate that was on my 300 engine.
The 240 driveshaft needed to be shortened approximately 4”. A local shop – Drive Train Industries – made the modifications [$65] by machining a shoulder in the front ‘knuckle’ and welding on the shortened tube. I did not balance the shafts and have not noticed any vibrations at speeds of 110+mph. The spline boot and center support/bearing were also replaced [$35].
The automatic transmission flywheel bolts have a short head height and the first one rounded off using an impact wrench. The socket had a slight bevel which needed to be ground flat to allow for more engagement and the remaining bolts came right out. Had to grind the head off the first one, then it was finger-tight.
I used the 240 flywheel. Had it and the clutch reconditioned/rebuilt – Lewis Brake and Clutch – [$139]. And new pilot bearing and release bearing [$59]. The clutch alignment tool recommended was a GM-10[$4.35], which worked perfectly.
The shifter came with the reverse light switch wiring pig-tail that is a direct replacement (read plug-in) for the automatic’s neutral safety switch wiring. I think it should only take once or twice (even for us grey-beards) of cranking the engine in gear, to become aware of that other new pedal down there.
I guess I got lucky with the gearbox as feels real tight and all syncros work well shifting both up and down. There is a strange ‘groan’ in third and forth gear from 1700-2000 rpm when lots of throttle is applied, but this is easily avoidable. The rpm is the same as before as the forth gear drive ratio is still 1:1. Speedometer error is about +5mph at highway speeds, but the odometer seems to be right-on. (??)
The front of the car was higher after removing the weight of the automatic. This was remedied by changing the springs, using the ones from the 240 and keeping the shorter top spacers that came on the 300. Ride quality improved also. As this wagon has hydraulic load leveling, adjustment can be made to the rear to bring the whole car down about 1 ¼ inches.
Finally, a new shifter and boot [$29]. After all - this is all that most people will ever see of all that beautiful work we did under our car.
Now go out and learn to drive with a very touchy turbo throttle (it’s now kinda like a switch).
Enjoy,
Jacob

All new parts obtained from ***********************

"The front wheels driven onto 10’ high ramps and then 10” blocks placed under "

WOW, I am surprised the 10 inch blocks would even reach the rear wheels....Did you have to use a front end loader to take the trans out.. with it that far off the ground ?

Leathermang,
Thanks for proof reading my post. Pardon the tiny typo. Of course it should have read 10 inch ramps for the front and then jack up the rear and place similar blocks under the rear wheels. I did have to lift a rear wheel a couple times to turn the driveshaft.
Jacob

I was wondering instead of using a 4-speed out of a donor 240D, would a 5-speed out of a 190D would work? It seems that many MB's use the same 4-speed automatic, probably 190D included. It would be great to have an overdrive gear.
Has anyone tried to use one?

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Someday, I'd like to take a good look at the 5-speed manual in the later model body to see if this sort of thing is feasable. But, I think the starter wart is on the wrong side of the transmission bell housing for this to work as a straight swap. However, if the 5-speed has a separate bellhousing like the cast iron 115 4-speed transmission, it may be possible to swap bellhousings in order to execute this conversion.

The manual tranny's FSM has photos with the wart on either side (and it's not a reversed image either) so I'm speculating that the older gassers may have had the starter on the left side of the engine and MBZ accomodated this by having different bellhousings bolted to the same tranny. Not being a gasser man, I've never payed much attention to them in the boneyard.

Somwhere (either in this Forum or on eBay) I recall reading about a 5-speed manual that came out of a 280CE. Anyone else remember this?

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Never a dull moment at Berry Hill Farm.

The 240 4-speed works well, however it does seem like a long step between second and third. I spend a lot of time in third at speeds of 30-45mph. Maybe a 5-speed would offer more accommodating ratios in the mid-range. Overdrive may be nice, but 3000-3400 at highway speeds does not seem excessive, as the turbo is spooling nicely. My 300TD seems to be pulling strong at 110+mph, but is limited by rpm. How fast do you want to criuse?
Jacob

At the higher RPM cruising speeds (70-75+ MPH) my '85 with the automatic sounds fairly loud, almost like a lawn mower. It would be nice to have the engine RPM's a bit lower at cruising speed, say around to where the turbo just starts to spool up or where maximum torque is reached. A few extra MPG's wouldn't hurt either.
I guess I'm just used to taking my wife's Tahoe on long trips since it runs 1750 RPM's @ 60 MPH.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Rode in a buddy's 02 firebird the other day, looking at his cruise rpm at 70mph made me sick..

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K