05' Gravely wb hydro pistol grip... I mow a lawn (everything is working fine), load up as usual, move to the next yard... and now the tracking is off and it creeps forward with the controls in the locked position. The left is creeping forward more than the right, and its tracking to the right in general. Ok.. so I know how to adjust the tracking, no big deal there. But w.t.h. knocked it out to begin with? Is there something within the Gravely linkage that can loosen? I havent found any problem or cause yet.