SUBSECTION 9B
PROPEL TRANSMISSION
gasket. Rotate the gasket as necessary to align with the slot
in the end of the pump drive shaft. Install the charge pump
onto the pump end cap. Rotate the charge pump until the
Do not lose any of the shims inside the plug
tang and slot engage. Be sure the charge pump sits solidly
(see Figure 9B-19).
on the end cap.
7. Install the four capscrews and tighten to 27-37 ft-lbs
torque.
INSTALLATION
Care must be exercised, when installing a new or over-
hauled pump, to prevent misalignment, which can lead to
premature pump malfunction. Install a new or overhauled
pump as follows:
1. Check the mounting flange on the drive unit, the pilot
diameter on the pump, the splined coupling on the drive,
and the splined pump input shaft for burrs or imperfections
that could prevent the pump from seating properly on the
drive unit. Carefully remove any imperfections by lapping.
2. Apply a slight amount of grease to the pilot diameter and
the pump shaft splines.
3 . Install the gasket on the pump and carefully install the
pump on the drive unit. Install the capscrews. Care should
be taken in tightening the capscrews to prevent misalign-
ment. Torque lubricated capscrews to 55 ft-lbs.
Figure 9B-19. Relief Valve Removal
4. Connect the charge pump inlet Iine, high pressure pump
inlet and outlet lines, and the case drain line.
Reinstall the valve by inserting the poppet, spring and plug.
5. Connect the electrical line to the controller.
4 . Using a slotted socket, remove the check valves from the
main pump (see Figure 9B-20). These check valves are car-
6. Install all sheet metal removed previously.
tridges and are interchangeable with each other. It is sug-
7. Perform the start-up procedure given at the beginning of
gested that these check valves be replaced in pairs.
this subsection.
MOTOR (41Q40)
DESCRIPTION
This is a fixed displacement, axial piston motor. One motor
is mounted on the left crawler, while another motor is
mounted on the right crawler. The motor receives flow,
through high pressure lines, from the pump to turn the out-
put shaft of the motor. Motor output shaft movement is
transmitted, through a propel gear case, to the crawler
driveshaft to propel the machine. Propel direction is deter-
mined by the positioning of the pump swash plate. The load
(working pressure) is determined by the external condi-
tions, (grade, ground conditions, etc.) and this establishes
the demand on the system.
REMOVAL
To remove a motor, proceed as follows (see Figure 9B-21):
Figure 9B-20. Check Valves
It is not necessary to remove the motor to per-
form repairs on the manifold or manifold com-
ponents. However, it is extremely important
5. Reinstall the check valves using caution to prevent dam-
that the disassembled motor be protected
age to the O-ring on the cartridge as the check valve is in-
from airborne dust. Contaminants introduced
serted in the pump. Torque the check valve to 80-90 ft-lbs.
directly into the motor have the greater poten-
Check that the valves are below the surface of the pump end
tial for causing damage. If this protection
cap.
cannot be provided, it is suggested that the
6. When replacing the charge pump, align the gasket so
motor be removed from the machine and re-
that the small relief valve port is open and not blocked by the
paired in a clean environment.