Simplicity AGCO Allis 2000 Series, Service & Repair Manual

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10 - 14
10 U-Type Hydrostatic Unit Service
Disassembly, Repair, and Reassembly
Assemble motor and pump cylinder block parts if neces-
sary and lubricate with clean hydraulic fluid. There is no
special orientation of piston to bore that needs to be
maintained; however, parts are not interchangeable
between cylinder block assemblies.
Hold the pump cylinder block (A, Figure 26) in the palm
of your hand with pistons up. Lubricate thrust plate and
lay it on top of pistons and block. Lower housing assem-
bly over cylinder block until shaft spline engages cylinder
block assembly. Be certain that pistons and thrust plate
remain in place. When properly installed a slight spring
tension can be felt when pushing on cylinder block.
Lubricate exposed surface of cylinder block with clean
hydraulic oil.
Install motor cylinder block assembly (B) using same
installation procedure as used for pump cylinder block.
NOTE: Pump cylinder block must be held in place while
installing motor cylinder block. A second set of hands is
helpful for this procedure.
Insert two case guide pins into main housing. Insert one
locating pin into pump (upper) portion of end section
(refer to Figure 19). Lubricate the slotted side of the
pump valve plate and slip it over locating pin and pro-
truding needle bearing.
IMPORTANT NOTE: The pump valve plate (A, Figure 27)
has two vee notches. The motor valve plate (B) has four
vee notches. Valve plates are not interchangeable.
Insert one locating pin into the motor (lower) portion of
end section. Lubricate the slotted side of the motor valve
plate and slip over locating pin and protruding needle
bearing. Use a small amount of petroleum jelly to hold
the valve plates in place.
Place gasket on center section using a small amount of
hydraulic fluid to hold it in place.
Place the eight screws that hold the end section to the
housing in their respective holes. Tighten these screws
equally and pull the two sections together. Torque
screws to 25-30 ft. lbs.
Figure 25. Attaching Swashplate to Trunnion Shaft
A. Control Shaft
C. Swashplate
B. Trunnion Shaft D. Pin (2)
B
D
A
1/4 in.
C
IMPORTANT NOTE: After screws are tightened, input
shaft MUST be able to be turned by hand. If shaft cannot
be turned by hand, disassemble unit and check pump
and motor valve plates to see if locating pins are properly
engaged in groove.
Install new lip seals. Install remaining components,
charge pump, and valves as described earlier in this sec-
tion of the manual.
Figure 27. Valve Plates
A. Pump Valve Plate
B. Motor Valve Plate
A
B
Figure 26. Removing Cylinder Block Assembly
A. Pump Cyl. Block
C. Pistons
B. Motor Cyl. Block D. Thrust Plate
A
B
D
C
C
Not
for
Reproduction