The tractor lift assembly does not support the right side of the mower. When the lift assembly Lever is at position 6 the left side has 3" clearance, but the right side has less than one inch [ the wheel that prevents scalping is what holds up the right side]. I can lower the assembly to 4 and the left goes down, but the right is still at less than one inch. What is causing the problem? Schematic is attached.