Assemble transmission cover – John Deere 318 User Manual
ASSEMBLE TRANSMISSION COVER
IMPORTANT: Do not nick or scratch lapped or
machined surfaces of the center
section, valve plates or cylinder block.
Keep pump and motor components
separate. They are not interchangeable.
Always use new seals and O-rings.
Damaged or used parts will leak.
NOTE: Lubricate all seals and O-rings with petroleum
jelly during assembly.
1. Install two needle bearings. Drive bearings into
housing until they are approximately 3 mm (0.118 in.)
above the surface of the housing using a 5/8 in. driver
2. Put clean John Deere Low Viscosity HY-GARD
valve plates and housing surface.
IMPORTANT: Pump valve plate (B) has TWO slotted
Motor valve plate (A) may, or may not
have slotted ports. Early models have
FOUR slotted ports (C). Quiet hydro’s
(later models) have no slotted ports. All
service or replacement plates will not
have slotted ports.
NOTE: The motor valve plates are interchangeable
between quiet hydros and early models.
3. Install pump valve plate (B) and motor valve plate (A)
over the protruding bearings and align slots in plates
with pins in housing.
A—Motor Valve Plate
B—Pump Valve Plate
C—Slotted Ports (4) (Early Models)
D—Slotted Ports (2)
316, 318 & 420 Lawn and Garden Tractors