Have changed the fluid and filter. Lift would not work prior to changing the filter. Had the two main valves rebuilt. Still wants to free wheel down a slight grade, almost come to a stop then the hydro catches up and it goes again to do the same thing. Pulled great on the same incline and level ground. Reverse works good also. Linkage pin on the damper spring plate is wore flat on the two sides that run in the slot on the cam. Any suggestions as to what the problem could be? Trunnion looks and measures OK.