Just replaced a new truck on SD45

[kountry mailman]

Replaced the drive truck on a SD45 because the brass gear was  worn.  Problem is still present, there is slippage as you hand turn the motor and give some resistance to the wheels and the motor is securely fastened to the truck.  Anyone know if you can replace the brass on the end of the motor shaft, or must you purchase a new motor?

[trainyardjp]

JP of Acton MA, USA writes,

I would probably replace the motor, itself, as trying to replace the worn gear might be difficult, if not impossible.
-JP