[Dick Linn]

Hope you had the internal gearbox spacers very precise so that the gears can't shift significantly when moving from forward to reverse. I think someone on this site calculated the end (axial)thrust of the gears and it was in the neighborhood of a couple hundred pounds...I can't recall. That could tear up the plastic. Also make sure nothing is misaligned and that the gearbox is securely but not overly tightened.

We used shaft clamp collars and machine washers to snug up everything onto the axle, not the spring or star washers or whatever you call them that came in the kit. We also were careful not to allow any axial play in the shafts, but then we have some dual-setscrew sprockets on the shafts between the wheels and the gearbox for our 4 wheel drive.

We didn't dop extensive testing, but a couple of us smaller guys (115 to 125 lbs.) rode up and down the ramp on top of the 'bot a couple of times and nothing seemed to come apart (one at a time. mind you). Note that with the sprockets between the frame rails and the wheels, the axles are cantilevered out from the frame a good inch or more beyond where they would be on a 2 wheel drive. I guess time will tell if it all holds up.