The rockshaft is a rod with a collection of levers welded to it at different angles that move things attached to them. The two outer attachments move the two rods that lift the deck. The big curved attachment determines the height of the mower deck when in the down position.

What is a Rockshaft?

(ˈrɒkˌʃɑːft) n. (Automotive Engineering) a shaft that rotates backwards and forwards rather than continuously, esp one used in the valve gear of a steam engine.

What is a Rockshaft control valve?

The rockshaft provides a means of raising and lowering equipment attached to the three point hitch. It also provides a means of setting specific operating depths for tillage equipment. A selective control valve (SCV) is installed to operate other equipment off the hydraulic fluid power system.