Considering a W115 300D donor for a manual conversion - PeachParts Mercedes-Benz Forum

diametricalbenz · #1 02-16-2006, 03:09 AM

I am considering using the motor which has relatively low blowby for a manual conversion to my W115 240D which I feel is getting tired. I want more power after having frequent near misses in traffic. I love the chassis with its gorilla knob and overall spaciousness. The 1976 300D W115 was presumed dead but after some glow plug cycles and cranking I suspect several glow plugs were simply burnt.

- If I convert it what will be required from the 300D car? And what else will I need to source.
Thus far from other posts I know that I will need the:
Differential
Speedometer
Radiator
Air Filter

- Will i need to shorten the driveshaft or can I simply swap the shafts from the 300D to the 240D?
- Will the shift rods have to lengthened or shortened?

Has anyone else done such a W115 conversion with success? Thanks for the help!

t walgamuth · #2 02-16-2006, 03:24 AM

i think in the 115 you wont have to do anything to the ds. the backs of the engine are in the same place i think four or five cyl.

tom w

diametricalbenz · #3 02-16-2006, 01:21 PM

Quote:

Originally Posted by t walgamuth

i think in the 115 you wont have to do anything to the ds. the backs of the engine are in the same place i think four or five cyl.

tom w

Presuming the rear position of the engine is the same would that imply that the shift rods don't need to be modified?

Any guesses about flywheel or clutch changes?

Thanks

#4 02-16-2006, 01:32 PM

The W115 300D should sit back 4" just like the W123's OM617.

diametricalbenz · #5 02-16-2006, 03:24 PM

So can the 300D driveshaft be transplanted to the 240D without modification?

Did you have to shorten the shift rods or were you able to get away without doing so?

#6 02-17-2006, 03:35 AM

Quote:

Originally Posted by diametricalbenz

Did you have to shorten the shift rods or were you able to get away without doing so?

I had to cut my shift rods about 3" but I didn't have to bend them. The 240D driveshaft had to be cut 3".

t walgamuth · #7 02-17-2006, 05:36 AM

but on the 123 chassis they put the front of the 240 and 300 in the same place, making the driveshafts and shift rods different lengths. on a 240 you will note a space at the back of the engine that is about equal to the size of another cylinder.

on the 115 chassis the rears of the engine are in the same place, so shift rods and ds are all the same.

i have done a 240 to 300 conversion on each chassis number.

if i am wrong about this the difference on the 115 will be very small, small enough as to be not noticable visually, and being a visual person i tend to notice things visually that most dont. (i tend to drive carpenters mad by spotting a quarter of an inch out of level on a 6' door header). (it really doesnt matter, i just do it to show off).

actually you will want to change the rear end too so while at it you may as well change the ds too. hopefully you will find a donor car with lower miles on it.

tom w