[Lil' Lavery]

The kit transmission can be converted into a 4WD rather easily by adding sprockets to your front drive axles (or wheels) and a second set of sprockets on the transmission output shafts.
As for problems, I have never expierienced any with the kit gearbox (save when we used a too large set screw). If your having problems turning, your wheels likely have too much traction. There are several ways to solve this:
1-wider wheel base
2-shaving "treads" off the tires
3-using omni-wheels on the front wheels
4-Using wheels with smaller contact points
5-Using wheels with a lower co-efficient of friction
6-wrapping your tires with wire ties to lower co-efficient of friction