[MrForbes]

I agree, it sounds like you are using the transmissions past the (unspecified by Banebots) design parameters.

256:1 reduction gives a LOT of torque, if you load the transmission too much, something has to give. These little transmissions just are not big enough to handle that much torque.

Is there any way you can reduce the load on the gearboxes? maybe add some type of counterbalance, or spring, or gas spring, or surgical tubing, or something?