nbsp 0183 32 Jaw breakers use an eccentric shaft to make the jaw move an inch and a half at around 400 rpm That makes 1500 engine rpm with a 540 rpm PTO So i dont know if it will be direct drive with just a torsion damper to get maximum fuel efficiency or with a 1 reduction so the tractor engine can run at 1900 to 2000 rpm to get more power