M115, are auto and manual different?
 

I know an m115 is a motor, but for my W115 220 I found a motor in a junkyard but the yard says it is a manual only motor.

Other than bolt pattern on the back of the crank I don't know what would prevent it from being used with an automatic.

The motor is a 1971 and my car is a 1972. Should it work?

The flywheel will be different

Does the candidate engine have a pilot bearing in the crank that would have to be removed for use with an auto trans? That's the only bolt-up difference I can think of. Carb linkage may be different to accommodate the trans throttle pressure rod.

Ill use the flywheel from my auto motor and pull the pilot bearing out of the back of the crank. My car is complete so I've got the linkage and everything on the auto car. The motor in my car starts and runs really well. But has a tremendous rod knock. I know that's an oxymoronic statement lol. But it starts quick and idles smooth, just a lot of metal on metal.



I swapped a 240D to manual (added pilot and changed covers), and then put a manual motor into an auto 240D (pulled the pilot and changed flywheels). So I'm familiar with how to do it, I just wanted to make sure on an M115 crank the auto and manual had the same bolt pattern.

Called the parts guy I deal with at the dealership. The catalogue specifies an automatic crankshaft and a manual crankshaft.

On m121s the bolt pattern is different between manual and automatic. This is what I was afraid of

But yours is a M115.

They all have the same 12 blot pattern.

I called the dealer regarding 1971 and 1972 m115s and he said the catalogue shows a part number for manual and a part number for automatic.


If you've got first hand knowledge that they are the same, I'd be happy to take your word for it lol, I'm having a heck of a time finding an engine.

Maybe ill call the yard and see if they can send me a pic of the back of the motor.

I am quite sure that the bolt pattern is the same.
And I am not aware of any differences between manual and auto cranks.
But the parts manual always knows better.

I have a 220 automatic motor still installed in a 115, but I don't know the condition of the engine.

You could email Ralf at www.treffpunkt-strich-8.de

He should know and he speaks English.

Ill send him an email this evening, thanks!

DP:

There is a reference in one shop manual to the depth of the centering bore on the front of the flywheel.

Flywheels for manual transmissions have a bore depth of 5mm.
Those for auto transmissions have a bore depth of 6.5mm.

That difference of 1.5mm might appear in the crank hub; the hub of the crank for manual trans' could be 1.5mm shorter. What to do? A spacer ring of 1.5mm thickness would put the face of the crank hub in the same place.

[The same situation appears with M116/117 engines; two different hub thicknesses, and a spacer.]

So I'm a goof. This works and I should know.

I took a motor out of an automatic 230 sedan, and put it into a manual transmission 230G. Had the motor on a stand and everything to reseal it and do a headgasket. Manual flywheel bolted right up.

It would stand to reason you can go the other direction just as easily.