DIRECT SUPPORT TROUBLESHOOTING PROCEDURES
EXTENDED SERVICE PROGRAM (ESP)
TRUCK, CARGO, 2-1/2-TON, 6X6, M44A3 SERIES TRUCKS (DIESEL)
DIRECT SUPPORT MECHANICAL TROUBLESHOOTING
This work package provides diagnostic and corrective procedures for the mechanical system at Direct
Support maintenance levels. The information in this work package is for use in conjunction with TM 9-
2320-361-34 and chapter 3 of this manual. The troubleshooting system index will help in finding specific
problems and solutions in Direct Support Mechanical Troubleshooting.
Operation of a deadlined vehicle without preliminary inspection
may cause injury to personnel and/or damage to equipment.
Notify your supervisor if corrective action does not correct
Direct Support Mechanical Troubleshooting.
TEST OR INSPECTION
1. ENGINE WILL NOT CRANK
Step 1. Remove starter (WP 0091 00) and check start drive gear and flexplate ring gear for broken
and missing teeth.
a. If starter drive gear teeth are damaged, repair starter (TM 9-2920-243-34).
b. If flexplate ring gear teeth are damaged, replace flexplate ring gear (WP 0337 00).
Step 2. Check engine for fluid locked pistons.
a. Remove all fuel injectors (WP 0319 00). Crank engine by hand and examine any fluid
expelled from cylinders. If fluid is coolant/water, perform malfunction 10, step 2. If fluid
is fuel, perform malfunction 19.
b. Turn crankshaft by hand. If crankshaft turns easily, install fuel injectors (WP 0319 00)
and proceed to step 4. If crankshaft turns hard, or does not turn, proceed to step 3.
Step 3. Check engine for mechanical lockup.
a. Remove fan drivebelt (WP 0084 00) and turn drive pulley of each belt-driven accessory.
If drive pulley does not turn, replace accessory component (WP 0087 00, WP 0081 00,
WP 0089 00 (Prestolite), or WP 0090 00 (Leece-Neville).
b. Remove valve cover (WP 0028 00). Turn crankshaft by hand at vibration damper and
visually check valve train operation. If valve train is not operating properly, check
camshaft and crankshaft gears, cam roller followers, push rods, and rocker arms for