I’ve installed some gear reduction motors I had laying around. I used some 9/32″ brass tubing to slip over the output shaft of the gear box, then I drilled a hole in the shaft and installed a set screw. After drilling the wheel hub hole out to 9/32″, I inserted the axle and motor assembly through the drilled out bushing in the suspension arm. Next I pressed the wheels onto the axles by hand. I soldered a twisted pair of wires to each motor and routed them up to the batteries on the main chassis.
It crawls over things fairly well considering the lack of torque and over all weakness of the gear box.
So, I now have proof of concept for a six wheeled drive train. Now I need to find some higher torque gear motors.
Here’s a video of it in action: