PTO Hydraulic Operation
When the vehicle is equipped for PTO operation, the transmission has changes to the hydraulic passages for the 3-4 shift valve. This allows the coast clutch to be applied in P, R, or N during PTO operation.
Non-PTO versions of the transmission have a source of fluid under line pressure to the 3-4 shift valve from the manual valve (OD circuit). In PTO versions the line circuit is the source.
Non-PTO versions of the transmission have an exhaust path for the coast clutch through the REVERSE circuit. In PTO versions, a separate exhaust path for the coast clutch exists.
Due to these hydraulic features, the upper valve body, lower valve body and separator plate of the PTO versions of the transmission are unique. Refer to the parts catalog for the correct usage.