TM 5-3805-258-24-1
T R O U B L E S H O O T I N G
Release the parking brake. Operate the machine
in each direction and speed. Make note of all noises
that are not normal and find their sources.
If the operation of the machine is not correct, make
reference to the CHECK LIST DURING OPERA-
TION for “problems” and “probable causes”.
CHECK LIST DURING OPERATION
Transmission
PROBLEM: Transmission gets hot.
PROBABLE CAUSE:
1.
2.
3.
4.
5.
6.
7.
Low oil level.
Restrictions in oil cooler or lines.
Magnetic screens in output transfer gear case
has too many restrictions.
Clutches not released all the way (drag).
Operation of ratio valve for the torque converter
not correct.
Oil pump has wear or damage.
Too much leakage in system.
PROBLEM: Transmission does not make a shift from one
speed to another speed.
PROBABLE CAUSE:
1. Adjustment of speed control linkage not correct.
PROBLEM: Transmission does not make a shift from one
direction to another direction.
PROBABLE CAUSE
1. Adjustment of direction control linkage not
correct.
PROBLEM: Transmission shifts slowly.
PROBABLE CAUSE
1. Low oil pressure.
2. Control linkages have damage or adjustment not
correct.
3. Air leaks on inlet side of oil pump.
4. Failure in the transmission pressure control valve.
T E S T I N G
A N D
A D J U S T I N G
PROBLEM: Transmission clutches engage very suddenly
(rough shifts).
PROBABLE CAUSE:
1.
2.
3.
4.
5.
Primary pressure setting of modulation relief
valve not correct.
Load piston in pressure control valve does not move.
Operation of pressure differential valve not correct.
Springs in the pressure control valve that are
weak or have damage.
Adjustment of control linkages not correct.
PROBLEM: Transmission does not operate in any speed
or clutches do not engage (slip) in all speeds.
PROBABLE CAUSE:
1. Low oil pressure because of:
a. Low oil level in transfer gear case.
b. Failure of oil pump or oil pump drive.
c. Air leaks on inlet side of pump.
d. Adjustment of modulation relief valve not
correct.
e. Too much leakage inside the transmission.
f. Failure in the transmission pressure control
valve.
2. Mechanical failure in the transmission.
3. Mechanical failure in transfer gears.
4. Mechanical failure in differentials.
5. Torque converter failure.
PROBLEM: Transmission engages but the machine does
not move and the engine stops.
PROBABLE CAUSE:
1.
2.
3.
4.
Mechanical failure in the output transfer gears.
Mechanical failure in a differential (front or
rear).
Mechanical failure in a final drive.
Gears in transmission do not turn because of:
a. Too many clutches engaged.
b. Mechanical failure in transmission.
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