So yesterday I bought a factory sealed rail truck, and of course the first thing it did on the programming track was split a gear.
The trouble is I have two others and they all seem to have the same problem: Resistance in the drive line.
The motors spin freely when I disconnect the drive shaft or run them without the differential cover installed. But when fully assembled they either make a grinding noise or don't run at all.
Before I disassemble this new truck and hope the white plastic or metal gears I've tried in the other two work better, does anybody have advice for resolving the problem?