the "fun" bit is getting everything marked and drilled accurately especially if the housing is still in the machine.

it would be easiest to do why you have pulled the engine for other work. drilling square to the housing so the bolts and the nose piece lines up square with the ring gear and thus th gear mesh correctly is difficult freehand. a mag drill would help with this. with the engine removed you could clamp a bit of heavy steel plate to the machined surface for the engine and use that to get enough step over with a mag drill and be almost perfectly square to that face.

the best way would be to set the housing up in a milling machine or radial arm drill so you can use the machined faces to be dead square as the casting could be out a bit remember these are sand cast parts.

Hi,
I am going to attempt to drill a D2 5U bell housing,
Does anybody have any photos/videos in addition to the template, also what starter motor did you use.
Thankyou, i will share the results

delco 42mt is the common one used.

Trainzkid, what truck or motor would that starter come from, and what voltage would it be? I have a late enough 5U that it has the starter hole already in the bellhousing and I might want to add a starter later on. Grant.

Hello Grantj
You can also use 40mt and 50mt but the usual one is the 40mt and its replacement 42mt. 24V is the voltage used mostly on the older machines. Some convert to 12V but I find it to be lacking in power especially on the larger machines.
There are cheap knockoffs available on ebay and for a hobby machine they are probably sufficient.
The best person to ask about starters on this forum is Old Magnet.

My understanding is many starters will work but you need a certain nose cone. Old Magnet knows the source.

Mounting a later style starter to the D2 models with factory hole is not that straight forward. Original D2 main engine starters had a smaller diameter drive gear than what is currently used for a non drilled conversion. The difference in diameters is about 1/8" thus requiring offset grinding of the factory hole about 1/16" or fancy offset machining of the starter drive end housing. The most common used starter motor is the 42Mt because it will have the least overhang of the engagement solenoid but the 40MT and 50MT will also work. Also required is the current 11 or 12 tooth RH helical drive gear and the D2 pattern drive end housing. No complete starter is commercially available in this configuration unless provide by a conversion supplier.