Anyone add gears to a non-powered MTH 6 wheel truck

I normally steal the power trucks off junked engines.

No, but I did power up an unpowered Atlas GP9 by getting the transfer gear assembly from them.  Prior to that I had used trucks, motors, and PS2 guts from a MTH RK F3 I won off Ebay.

If the MTH gear assy is anything like the Atlas assy it's a drop-in assy.

The MTH parts worked fine in the Atlas GP9, but the Atlas truck sideframes (which have better detail) wouldn't fit the MTH trucks.  In addition, the Atlas trucks "seem" to roll a bit better/quieter.

What 6 wheel trucks?  I took Williams 6 wheel trucks (SD45, FP45, U33C, Dash9, FM models) and used them to power a dummy MTH C30-7, also used the MTH side frames which are better.

I have a dummy MTH SD40-2 that I want to power. Naturally the trucks are missing the transfer gear assembly. I notice the Weaver trucks, MTH and Williams look like they all came from the same supplier.

Have any of you removed a transfer gear assembly? It appears on the side opposite the gear there is a bolt head or some sort of cap. Is it removable? The gear itself appears to be pressed on.

Between the locos I "junk" because they don't run well - or whatever -  and those I can buy cheap swap meets because they are already junk, I have are plenty of powered trucks and parts

Next time at a swap meet, check for a seriously distressed two-motor diesel - cracked shell, doesn't run, etc.  Take it home and take it apart, and almost certaintly you will have: one good truck, or the parts to make one good truck, and one good motor.  (My experience is the can motors are almost never bad, but it could happen)

What I am trying to find is someone who has gone through the process of removing the transfer gear assembly from a power truck. I have a power truck (4 wheel) candidate, but do not want to "mess" it up because I did something wrong in the removal process.