I posted this a while back with no response. I'll try a different way of explaining what this zero turn does. Cannot find anything in manual because its a sealed trans and suppose to not need maintenance. At low speed I am holding the steering handles steady. The mower bucks. Doesn't do this at high speed. Most of you know what is meant when an engine is hunting. This is similar, except it's in the trans. Trans are full of oil. What could cause this.