That's the only problem that I have with those tanks, too. They have a kind of slipping mechanism that slips too easily.....better than broken gears though, I reckon. If someone ever comes out with metal gear box replacements, I will glue that slipper thingy in place and have a much better tank, but until that day the best idea is to drive in places that you can turn easily, like sandy soil or concrete.

Maybe you and your friends could set up an urban battlefield in a parking lot.

Good Luck!
Jason