Grinding Gears
Hello, Can anyone please help diagnosing a problem I'm having with my Tamiya Fox? It was running fine, and all of a sudden there is a sharp grinding sound coming from the gear box. It only happens while going in reverse, and when there is resistance. When held off the ground you can go from full speed foward to full reverse without any issue, but when it's on the ground, even the slowest reverse creates a loud gringing noise. I've taken apart and re-worked the gearbox several times. There are no chipped teeth on any of the gears. I know this is an older car, but can anyone offer some suggestions? I'm at a loss. Tony