Just thinking out loud, is this is a bolt on fit??

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85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

Not exactly a bolt in. I'm pretty sure the bellhousing will bolt up, but you will need to modify the shift rods for length, as well as the length of the driveshaft and the interface of the transmission and crossmember. It's all doable, but takes a bit of work. Search the diesel section for "four speed conversion" or "manual conversion" and there are some threads with details from people who've done it.

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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.

Not a 300cd, but I put a 4-speed from a 1972 220d into a 1980 300d.
The shift rods were the right length, and the crossmember did not need modification.

great info. how, then, do the w115 manual transmissions differ from the w123 ones?

they don't on early 123's. later 123's had aluminum case but they are 100% interchangible.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

So I can have my indy swap a 4-speed manual transmission from a 1973 220 fit into an 85 300CD with minimal fuss?! How hard is this to do myself? I am mechanical inclined but only have done brakes, rotors, ATF changes, moderate stuff. How high on jack stands do I have to get the car up to swap out the transmissions?

Getting the transmission out isn`t too bad (4-spd) think the later style (82-83) weigh 54lbs. not too sure of to older iron boxes. they weigh a bit more.

I have dropped both types in the PNP`s. w/o much difficulty, lower it down to my chest, then roll it to one side. not sure how high they are jacked up on the welded wheel stands.

Getting one back in will be easier with a transmission jack or do the balancing act on a floor jack but risky it it decides to slip off and land on you.

I bought a HF 450lb trans jack, has 4 castor wheels, need to measure the height of what ever type jack you use, plus the height of the bell housing, then you will need the front of the car high enough to clear the cross frame under the engine.

Now if you are Charles Atlas or some body builder type, or a young guy full of Testosteron, then you can just one arm it up into position.

Note: I have never seen a w115 transmission to compare to the 123, so no help there

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I've had an '85 300cd that some retard installed a 240d trans into. drives horrible. don't do it. gears are too short, you gain nothing. there's a reason mercedes never put manuals behind a turbo charged engine. every time you shift, the turbo has to build up pressure again, which isn't the case with an automatic as they shift faster. from a 240d it's a simple bolt in though, if you find a donor. and then a 5-speed and maybe a longer geared diff and you'd have something.
I yanked that junk out and put an auto trans back in, so much better.

The propshaft length and transmission length information can be found here

Gearbox comparison & drive shaft lenghts & colour codes - Benzworld.org - Mercedes-Benz Discussion Forum

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Never was aware of this issue, thanks.

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

the early tranz bell has a flat case design instead of the sloaping case--it just does not have the top bell to gearbox inside bolts so the bell is missing its hump because the tranz is flat cased.

if your 85 auto is working good you already got the best trans/gear setup of any w123 and i wouldn't alter that red coupe, my burgendy 85 cd i probably would--but only if my auto went on me.
edit--I just saw the other thread---- well you need to get a pedal/clutch and 4 speed shifter assembly from a w123 240D somewhere-- 5 speeds are different--unless you use a toploader type tranz from something else- try here, i have before,but best luck is to find one in a yard.

the 4 speed is 4th gear direct so no more overdrive and would first gear be ideal like it is now with the 722.4 with the special first to go with the 2.88.
you would need to go with at least somewhere like the 3.23 rearend--the 240"s have 3.55.

Yeah, I think I will sty with the auto. I think it is a 722.3 tranny with a 2.88 differential.

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

Well that is your opinion and you are entitled to it. But there are a lot of us who have made the swap and have not had the slightest hint of turning back. My 300D with a 4 speed is a total delight to drive. It is true that at full throttle your boost will stay up on the automatic, but the loss you have in power transfer threw that automatic is very high. That is why on a good running automatic you run 0 to 60 in 17 seconds and on the four speed you can bring that down to 14 seconds. Now that 14 seconds is an estimate because I don't "can" my cars. I keep them tip top and ready to run cross country at anytime - always ready to go. And to do 0 to 60 in 14 seconds would load it up more then what I wish to do with my 300D.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!