Terra Force 3PT Hitch 42" Rotary Tiller The YJC Chain Drive Tillers are the most popular of the tillers, they combine efficiency and price in such a way that it leaves an obvious value that is hard to walk away from. The gear box on the top of the tiller has sprial cut gears, which will run much quieter than standard cut gears, this gives a more pleasant experience, and longer lasting gears, which is why they warrant them for 5 years.