TO-35 Lift Cover Broken and Why

I just bought a 1955 Ferguson TO-35 #66004 from an auction company. The lift cover looks like it was broken in half, the brace you see appears to help keep the front broken half in place. Maybe some of the experts at Ferguson Furrows could tell me what would cause such damage. September 4, 2014.

The top cover looks like it was split and the center housing looks like it was broken. You are going to need a new top cover and a new center housing. This usually happens when the height adjustment for the lift arms is set incorrectly and the lift piston travels farther than it is supposed to which means it pushes the link connected to the internal rockshaft arm into the bottom of the top cover and breaks the top cover. This can happen when the height adjustment stop is not set correctly, when the relief valve sticks or when the wrong relief valve is installed. It can also happen when an extremely heavy load is placed on the lift arms and the relief valve does not open. The hydraulic system tears itself apart.

Your best bet is to find a good used top cover and a good used center housing. Top covers and center housing from later production tractors can be used to replaced the original but the relief valve used should always be the one with an operating pressure that is correct for the original hydraulic system.

Over the years the thickness of the top cover was increased and the strength of the center housing was increased by beefing it up. If a newer thicker top cover or a later center housing is used you may need to change the tube that goes from the top of the pump to the bottom of the top cover.