SECTION 7
TRANSMISSION
FIGURE 7-39.
the forward and reverse positions. The gauge should
a. Movement of the unit must be safely restricted.
indicate 150 to 180 PSI above case pressure (10.55 to
b. Remove the cover from the right-hand side of
12.66 kg/cm2) in each direction.
the frame at the drive drum.
d. If the pressure is not within the specified limits,
c. Connect a 10,000 PSI (700 kg/cm2) gauge to
replace the low charge pressure relief valve. If this fails
the REVERSE check port (see figure 7-39).
to correct the pressure, troubleshoot the system as
d. Start the engine and set Park Brake. Increase
specified in Table 5-2B.
engine speed to 1500 RPM.
e. Slowly move the Direction-Throttle Control Bail
WARNING: Changing the quantity of shims in the relief
in the Reverse direction from neutral and bring the unit
valve is not recommended
to stall. Observe the pressure gauge. With the
transmission stalled, the gauge should indicate 5500
7-162. CHECKING HIGH PRESSURE RELIEF (see
PSI (386.7 kg/cm2). If not, stop the engine and remove
the two (2) high-pressure relief valves. It will be
CAUTION: Transmission should NOT be stalled at high
necessary to disconnect the two (2)
pressure relief for periods longer than 15 seconds.
high-pressure hoses.
7-163. The pressure in the high-pressure lines should be
f. Reverse the relief valves in the manifold ports
5500 PSI (386.7 kg/cm2) when the transmission is in a
and recheck at the REVERSE check port. If the
stalled condition. Two (2) high-pressure relief valves are
pressure is normal, replace the relief valve originally
located in the motor manifold as shown in figure 7-39.
removed from the reverse side of the manifold. If the
Two (2) check ports are located at the side of the
pressure
remains
abnormal,
troubleshoot
the
manifold for checking the setting of the relief valves.
transmission as specified in Table 5-2B.
Check the high-pressure valves as follows:
WARNING: In order to check the high-pressure relief
WARNING: Changing the quantity of shims in the
valves it is necessary to bring the unit to
relief valves is not recommended.
stall. CAUTION must be taken to ensure the
g. If pressure reading at Reverse port was normal
safety of personnel when attempting to stall
then connect the gauge to the FORWARD check port
the unit.
(see figure 7-39).
h. Start the engine again and increase speed to
1500 RPM.
i. Slowly move the Direction-Throttle C6ntrol Bail
in the Forward direction from neutral and bring the unit
to stall. Observe the pressure gauge. With the
transmission stalled, the gauge should indicate 5500
PSI (386.7 kg/cm2). If not, stop the engine and remove
the two (2) high-pressure relief valves.
j. Reverse the relief valves in the manifold ports
and recheck the pressure at the FORWARD port. If
the pressure is normal, replace the relief valve originally
removed from the forward side of the manifold. If the
pressure remains abnormal, troubleshoot the system as
specified in Table 5-2B.
k. Stop the engine and disconnect the gauge.
Install all plugs and tighten all fittings
FIGURE 7-39
7-31.
