got a ford 7710 model number fc315m will not move it acts like it want to but it won't move. The clutch is good it's in the dual power. When I put air in dual power line you can hear the air going straight into the rear end. when you shift dual power you can hear cynoid move and within few minutes you can hear the air into rear end again. I split the tractor and got the dual power on the work bench. the flat split oring between the oil gally looks good and took fitting of pressure line and can blow thru filter does anyone know how it comes apart or have drawing or have any idea what would cause this I am trying to tear it down to check clutch discs in there. also on the bench when you shift the collar back and forth it doesn't seem to lock up you can turn input shaft separate from output