TM-9-2350-311-20-2

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR CAB, ARMAMENT, SIGHTING AND FIRE CONTROL, ELEVATING AND TRAVERSING SYSTEMS AND ASSOCIATED COMPONENTS

DECEMBER 1993

TM-9-2350-311-20-2 - Page 510 of 828

TM 9–2350–311–20–2

9–8

Change 2

9–3

ELECTRICAL CONTACT ARM ASSEMBLY

This task covers:

a.

Removal

b.

Disassembly

c.

Assembly

d.

Installation

e.

Cleaning

f.

Adjustment

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

Contact brush adjustment gage (Figure E–1, Appx E)

Soldering torch kit (item 13, Appx H)

Soldering gun (item 12, Appx H)

Materials/Parts

Cleaning compound (item 9.1, Appx D)

Flux (item 15, Appx D)

Lockwashers (5) (item 55, Appx G)

Lockwashers (4) (item 56, Appx G)

Lockwashers (6) (item 64, Appx G)

Lockwashers (2) (item 79, Appx G)

Rosin core solder (item 34, Appx D)

Sealing compound (item 30, Appx D)

Shims (V) (item 111, Appx G)

Equipment Condition

Disconnect batteries (TM 9–2350–311–20–1)

a.

Removal

WARNING

While performing all procedures in this section except for adjustment, disconnect the battery ground

cable at battery terminal to cut off cab electrical power. Failure to observe this warning could result in

severe burns and electrical shock, resulting in injury or death.

NOTE

Perform these procedures for each of 3 or 5 electrical contact arm assemblies.

1

Disconnect ground straps (1) and ground wire (2) by removing one cap screw (3) and lockwasher (4) from

each side of the electrical contact arm (5). Discard lockwasher.

2

Remove electrical contact arm (5) by removing four cap screws (6), four lockwashers (7), and shims (8).

Discard lockwashers and shims.

3

Disconnect five electrical leads at quick disconnects (9).