When you move the levers or hit a bump, the hydro's seem to jerk. So.....I replaced the dampeners yesterday. This did help some but the jerking motion is still there. It makes it hard to hold a straight line. What do you think my problems could be? It's on a 2001 Scag 61/27LC kawi w/1370 hrs. It's till under warrany until August. Please guide me in the right direction.