TM 9-2320-279-34-1
Parts, Tools, and Test Equipment (Cont)
2-5. REPAIR PARTS. Repair parts authorized for use at the direct support and general support
maintenance level are listed and illustrated in Repair Parts and Special Tools List (RPSTL),
TM 9-2320-279-34P.
Section Ill.
TROUBLESHOOTING
2-6. TROUBLESHOOTING INTRODUCTION. This section contains step by step procedures for
identifying, locating, isolating, and repairing M977 series vehicle and component malfunctions. Refer to
TM 9-2320-354-24&P and TM 9-2320-355-24&P to troubleshoot crane problems on the M984 and M985E1
vehicles.
2-7. TROUBLESHOOTING INSTRUCTIONS. The Troubleshooting Fault Symptom Index (Table 2-1)
lists common malfunctions by vehicle system. The Troubleshooting Subject Index (Table 2-2) lists common
malfunctions alphabetically. The Troubleshooting Procedures (Table 2-3) lists each malfunction followed by
tests, inspections, and corrective actions.
a. This manual cannot list all malfunctions that may occur, nor all tests, inspections, or corrective
actions. If a malfunction is not listed or is not corrected by listed corrective actions, notify the supervisor.
b. Do the tests and inspections in the order listed, and try to return the vehicle or component to
operation after each test, inspection, and corrective action has been performed.
c. Refer to the figures and foldouts listed below while doing troubleshooting. They will help to isolate
and locate troubles and get the vehicle back in service as quickly as possible. Foldouts are found at the end
of this manual.
Figure 2-2
Figure 2-3
Figure 2-4
Figure 2-5
Figure 2-6
Figure 2-7
Figure 2-8
Figure 2-9
Figure 2-10
Foldout 1
Foldout 2
Foldout 3
Main Control Valve (M983)
Outrigger Control Valve (M983)
System Back Pressure (No Load) (M983)
Pressure Tester Setup (M983)
Power Distribution Board Wiring Diagram (M983)
12v Electric Motor Tester Circuit Schematic (M983)
12v Electric Motor Tester Circuit Wiring Diagram (M983)
Engine Arctic Heater Wiring Diagram
Engine Arctic Heater Coolant Pump and Motor Tester
Hydraulic Schematics
Crane Wiring Diagrams
Crane Electrical Schematics
Troubleshooting Index
Table 2-1. Troubleshooting Fault Symptom Index
Troubleshooting
Procedure
Page
ENGINE
1. Engine high idle does not operate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
TRANSMISSION
1. Transmission oil temperature gage stays over 2500F (1210C). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
2. Transmission noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
3.
4.
5.
2-2
Transmission will not shift into gear, slips out of gear, or operates erratically . . . . . . . . . . . . . . . . 2-15
Oil leaking at converter housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Excessive creep in first and reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
