Guys, some horizontal motors did indeed come with nylon drive gears. The nylon gear extends ever so slightly beyond the bottom of the motor casting and is not interchangeable with motors with all metal gears. If a truck came with motors with nylon gears you can't replace the motor with one with metal gears. It won't mesh. The metal gear will miss the brass spur gear on the truck. Subsequently the nylon gear will bind the brass spur gear on the truck that came with metal geared motors. A discovery I made while servicing/repairing.
Nylon geared motor on the left. Even the motor casting is a bit different both on the top and bottom.
