Why am I killing gearmotors

[TheBennyB]

I would check the alignment from the sprocket through the bogies to the idler. If it's not in line the track may be binding as Cooper mentioned.

[Rvjimd]

Those are the same motors that I started using on my Oliver diecast conversion and I was breaking teeth in the gear head. I spent a bit more on the planetary versions and they seem much more reliable. It was breaking teeth on the final gear in the set. The more expensive planetary version also seems to have a better motor and was not as noisy and did not create the electric interference trouble that i was having with the sabertooth controller.

As for one sided issue, is one motor actually running reverse of the other? You wouldn't expect it to be different but I seem to see the same thing. On my Dozer I think one is running the opposit direction for forward. I wonder of the gearbox is somehow skewed toward a single direction as forward. I don't remember if the power tabs were labeled red and black or positive/neg to indicate a "normal" forward running?
Jim

[sparkycuda]

Interesting that you were breaking the teeth on final gear. In a spur gear setup, that is the gear producing the most torque, all concentrated on a single tooth. Planetary gearsets typically have three or more gears meshing on the output, spreading torque over several teeth, so less strain on individual gears. On 1:1 bulldozers, some final drives distribute torque over 5 or 6 planet gears.

Always look for the binding conditions others have mentioned, but using planetary sets do have an advantage in large torque applications.

Ken