1939 #12 grader question

[Jack]

A private road association needs a little help. They have a #12 grader reported to be 1939 built, "blew up the starter drive" I'm told. What engine is in this grader and what crawler tractor used the equivilent engine? What would the serial number series be? I checked back through old threads, didn't find anything 1939. I gather that this is a D6XXX engine but not sure of it. Could it be an old 3 cylinder?

The machine isn't where I can see it at this time and I don't know exactly what is wrong. I just got a call for help. Any help we can get will be appreciated I'm sure. Thanks,

Jack

[Old Magnet]

Hi Jack,
There were a few #12's with a 6M model designation from 39 -42 that used a gasoline version of the 4600 engine
but more than likely it is a 9K model from 38-45 that used the D4600 engine
common to the 4R/5R D6's.

[Jack]

Hi O.M.

My brother told me it had a pony motor starter so that rules out the gas engine. I'll send on this info. It'll be a good place to for them to start from. Many thanks,

Jack