CHAPTER 4. TROUBLESHOOTING - TM-9-2520-254-340047

CHAPTER 4

TROUBLESHOOTING

4-1. Purpose and General Instructions

b. Functions

of Components. Refer to

paragraphs 2-12 through 2-26 for explanations of

NOTE

hydraulic operations and power flow through the

Information in this chapter is for use of

transmission components.

Ordnance maintenance personnel, in

c. Operating Instructions. Refer to end item

conjunction with and as a supplement to

operator's manual for instructions on operating the

the troubleshooting section of end item

transmission while driving the vehicle in which it is

organization manual. It provides con-

installed.

tinuation of instruction where a remedy in

d. Oil Supply. Refer to paragraph 1-6 for oil

the organizational maintenance manual

supply information.

refers to Ordnance maintenance personnel

e. Adjustments. Refer to paragraph 5-63 for

for corrective action.

adjustment procedures.

a. Operation of a deadlined vehicle without a

f. Oil Pressures. Refer to table 1-1, paragraph 1-

preliminary examination can cause further damage

7, for oil pressures.

to a component and possible injury to personnel. By

careful inspection and troubleshooting, such

4-3. Troubleshooting--Before Removal or Op-

damage and injury can be avoided. In addition, the

eration

cause of faulty operation of a vehicle or component

a. Do not operate the vehicle prior to completing

can often be determined without extensive

the procedures described in this paragraph. Refer

disassembly.

to paragraph 4-1 for the purpose of these in-

NOTE

spections. Inspect for oil leakage. Visually inspect

This chapter contains inspection and

all split-lines, connections, covers, output shaft, and

troubleshooting procedures to be per-

plugs for oil leaks. Oil leakage at split-lines may be

formed while a disabled component is still

caused by loose bolts or defective gaskets. Tighten

mounted in the vehicle as well as after it

bolts where leakage is found. If leaks continue,

has been removed.

install new gaskets.

b. The inspections made while the component is

NOTE

mounted in the vehicle are, for the most part, visual

Inspect transmission again for oil leakage

and are to be performed before attempting to

after starting vehicle engine (para 4-4).

operate the vehicle. The object of these inspections

b. Inspect transmission assembly for loose

is to determine the condition of the component and,

components and loose, disconnected, or damaged

if found defective, to take precautions to prevent

linkage. Check linkage and operator's controls for

further damage.

damage, wear, binding, or improper adjustment.

c. The troubleshooting performed while the

Proper adjustment and operation of shift and

component is mounted in the vehicle is that which

throttle control linkage are essential to efficient

is beyond the normal scope of the using

performance of the transmission.

organization. Check the troubleshooting section of

4-4. Troubleshooting--Before Removal and

end item organizational manual, then proceed as

During Operation

outlined in this chapter.

a. General. If the inspections in paragraph 4-3 do

d. If the component alone is received by the

not reveal the cause of failure, and the vehicle is

Ordnance establishment, inspection should be

operable, further troubleshooting is necessary. Do

performed to verify the diagnosis made when the

not remove the transmission from the vehicle until

component was in the vehicle. This inspection, to

the causes of trouble listed in table 4-1 are checked.

uncover further defects, or to determine malfunc-

Refer to paragraph 4-3 for the purposes and scope

tions, is particularly important because it is often

of these troubleshooting procedures. To make a

the only means of determining the malfunction

thorough check of transmission performance, be

without complete disassembly of the component.

sure the vehicle engine is properly tuned and that

4-2. Operating Characteristics

the transmission oil level is correct (para 1-6).

To perform effective troubleshooting, the mechanic

Inspect again for oil leaks after starting engine.

must have a thorough knowledge of--

b. Troubleshooting Table. This condensed

a. Construction Features. Refer to paragraphs 2-

troubleshooting information will assist mechanics

1 through 2-11 for description and function of the

in diagnosing and correcting malfunctions in the

transmission components.

4-1