Which starter drive for 70D 3819 Motor Grader?

Those are the right part numbers. All those late graders and D6's, direct start or pony, used the same 7B6253 ring gear (112 tooth)

Are you sure you received the right drive RH helix, 11 or 12 tooth.
They also make a LH version.

Have you actually tried a fit up...what seems to be the problem?

When I called the company, I specifically stated that I needed an SAE 3 145 and 3-293 or 3-293A. They sent me an SAE 3 180 and a LH drive. I called and made a stink. I received the new parts in the mail today and yes they are correct. The drive gear came in a box labeled 3-293A and when compared to the picture on Old Mag Cat the direction of the teeth go the same way.

I have fit it all up. When I energize the solenoid, it hums quite loudly but nothing else occurs. It doesn't even sound as if it is attempting to engage the starter drive with the ring gear.

I pulled the starter out and removed the drive gear to see how it fits up with the ring gear by itself. Holding the drive gear more or less in the center of the hole machined in the housing, the teeth of the drive gear overlap with the teeth on the ring gear by about 1". There is no way that any type of meshing will occur. The drive gear has to be pulled to one side of the hole in the housing to even get close to where the teeth mesh, but even then, holding the teeth against each other they don't seem like they are a good fit. The teeth don't appear to mesh (but I may not know what I am looking for either).

Somethings strange, haven't had that kind of problem with a factory hole.
Try this,
Put the drive back on the starter, take the solenoid housing off exposing the plunger. Mount the starter to the clutch housing and use the plunger to manually engage the drive if you can. If no go loosen the mounting bolts and see if it will now engage. Meshing of the gears has to come as a result of the helical motion which you don't have while manually engaging but should be close and they usually will mesh.

raklet,

I recently converted my " new" Cat 12E to direct start with an MT 50 starter. There's an adapter plate that goes between the starter and clutch housing that moves the starter outboard and to the rear a bit. Are you sure that one isn't needed for yours too?

Somethings strange, haven't had that kind of problem with a factory hole.
Try this,
Put the drive back on the starter, take the solenoid housing off exposing the plunger. Mount the starter to the clutch housing and use the plunger to manually engage the drive if you can. If no go loosen the mounting bolts and see if it will now engage. Meshing of the gears has to come as a result of the helical motion which you don't have while manually engaging but should be close and they usually will mesh.

[quote="Old Magnet"]Somethings strange, haven't had that kind of problem with a factory hole.
Try this,
Put the drive back on the starter, take the solenoid housing off exposing the plunger. Mount the starter to the clutch housing and use the plunger to manually engage the drive if you can. If no go loosen the mounting bolts and see if it will now engage. Meshing of the gears has to come as a result of the helical motion which you don't have while manually engaging but should be close and they usually will mesh.[/quote]

That's a good idea. Will do that first thing this morning. Thanks.

No adapter required. That didn't get used until the D333 & D330.