I'm about to go up and buy a engine and manual 4 speed and conversion from a 1980 240D. I want to put it into my 1975 W115 300D automatic that has a blown engine. Does this bolt right up? Clutch pedal, driveshaft and such?

Or do i need to find a w115 donor to get my engine and tranny?

Thanks

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

I believe that the major difference to the engine is the location of the oil filter canister. I think you can swap over this part from the old engine?

No idea on the trans, driveshaft, pedals, etc.

If you are converting from auto to manual trans, there may be other stuff (throttle linkage, trans support brace) that you'll need.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Skip the 80 engine and look for a W115 240D. There are many differences. Some can be easily overcome and others are very difficult. The biggest problem is the oil filter location. The W123 engine oil filter housing will not fit in the W115 chassis. The engine blocks are different in this area and the W115 parts can't be swapped.

Differences between the W123 and W115 transmission setup include the driveshaft, the transmission cross member, Shift linkage length, speedometer cable length (or type Getrag vs Iron), clutch pedal and backup light wiring. The shifter is the same but is specific to the transmission type (Getrag vs Iron). Getrags usually show up in 81 or newer chassis.

The W115 300D engine mount arms are unique to that engine. This is because the 5 cylinder was a tight fit in the W115. As a result the length difference is spit and the engine moves closer to both the radiator and the firewall. The radiator, shroud, radiator hoses, some heater hoses, oil cooler, cooler hoses, oil pressure line, vacuum pump lines, AC hoses, exhaust, throttle linkage and air cleaner are all unique to the W115 300D and do not interchange with the W115 or W123 engine at all.

The power steering pump and mounting is also different on the W123 engine and so are the accessory drive pulleys. You could use your 300D radiator with a W115 240D shroud despite the small differences.

77-79 W123 240D engine side throttle linkage is compatible with the W115 setup but not with the stock W115 240D exhaust manifold. The W123 240D exhaust manifold fits in the W115 chassis but is very close to the heater hoses and will need a custom engine pipe. W123 intake and air cleaner also clears the W115 chassis but I haven't checked clearance issues in an AC car.

If you get tempted to fabricate and mix and match W115 and W123 240D parts be aware the W123 240D uses an MW pump that requires an external oil supply the W115 block doesn't have a provision for. Also, the MW pump will not clear the W115 240D oil filter stand or any block with threaded core plugs. If you get tempted to experiment with the newer pump on the W115 240D block you'll need the oil filter stand from the blown 300D. That will necessitate custom oil cooler lines.

If you use a W115 240D as a donor you'll have very little trouble. You will need to add a hole to for the reverse light cable in the transmission tunnel (if you're a purist) and one for the clutch hard line. You'll also need to modify your master cylinder reservoir for the clutch hose connection (easy). Everything else swaps over directly.

The glow system on the W115 240D is completely manual and while you could maintain the original 300D glow control I can't be sure how it will react to 4 glow plugs instead of 5. The 80 W123 engine is the first year for pencil plugs which will not work with the 300D loop type glow control.

Keep in mind the differential in your 300D is a 3.46 and the 240D (W123 and W115) are 3.69. If your car has AC and PS and you live in the mountains the 3.46 may be too much. Speedometers are calibrated to diffs so you need to swap the 240D speedo in if you use the 3.69. If you do that you lose the glow light found only on the 300D speedo face.

I'm sure I missed a few things and I'm happy to answer questions. I've owned and parted several examples of the cars in question. I can tell you there were many changes from the W115 240D to the 300D and many more still when the W123 came along.

If you decide on the hard way research everything very carefully. With enough money and time anything is possible but...

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1969 220D 5 Speed (OM616)
1983 240D 4 Speed
1985 300D Auto 376K
1985 300D Auto 275K

Thank so vt220. That is what I needed. I just want a mostly drop in. My car is a 1975 300d automatic. Only 50000 miles on it. I really just need an engine. But if I get a 240 I want a manual. I've done a few manual swaps.

Sounds like I need parts from 115. I'll keep looking

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

The answer, from my point of view, is that anything will fit in anything if you have enough time, money, and patience. I have time and patience and seem to scrape up barely enough money so I get to do weird engine swaps. If you need essentially a bolt-in it sounds like this is not your swap. I haven't done one But I'm guessing VT220D has given you THE info.

Dan

I agree its a good idea to get a matching chassis engine for your car. Best to buy a running parts car with issues if possible especially if changing engine size.

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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'm having a hard time finding an engine for this car. I'm starting to think I may need to do something custom. I have a perfect running 1998 e300 turbo diesel 606 with a blown transmission that i am using for a parts car. Will that engine bolt to my w115 tranny ?
That would be a fun car. I wouldn't mind doing some work to get to use my 606 engine.
https://www.youtube.com/watch?v=KgJNpPRyapo

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

Nope, you would have to be really keen as you'd need a lot of surgery to get a 606 to fit

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1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

Hey Bio, I suggest running a want ad for your engine. You never know who might have one lying about.

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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.