4300 3 point lift

When the 3 point lift rockshaft control lever is in the down position and raised until the lift starts up the lift goes all the way and loads up as if still trying to raise. The lift can be stopped anywhere in it's travel by slightly moving the control lever down. The lift works the same when all the way up and lowered. I have removed and inspected the the rockshaft piston asembly under the seat and found no sludge or other restriction in the the pistons operation. Any help?

Glenn

I would check the feedback linkage to be sure it is connected properly. On the left lift arm as you are standing behind the tractor, you should see a rod connected near the rockshaft pivot point. It is held on with an E-clip. I have seen these clips fall off and the rod comes unhooked. If it is connected at the rear, follow the rod forward and be sure it is connected at the front of the housing.

The feedback linkage was in good condition but as I was inspecting this I found a sheared pin. The linkage is fastened to a C shaped arm that has a rolled pin that was sheared off. If I had not inspected the linkage it may have been some time before I found the pin problem. I would guess that somebody adjusted the linkage wrong and sheared the pin.

Thanks for your help.
Glenn