- 25 Apr 2020
I am trying to figure out the differences between the different motor bricks in USA Trains locos and a good source for parts for each, as needed. The GP7, GP38, and F units, have the same brick and I have ordered them from Only Trains. R22-115 for those. Now that Greg pointed out that the Alco S4 uses a different motor brick, I see that Only Trains also has those and now I have a reference number and a visual there. R22-12 for the S4. So the question I have is what motor brick goes in the 44 ton switcher? I don't see those on Only Trains or anywhere else so far. They have tabs on the end of the motor brick for couplers. So can they also be found for sale as a whole unit? Or, is this a case where you get wheels, axles, gears and motors (as needed) and rebuild the ones you have?