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 265 of 828

TM 9–2350–311–20–2

Change 2

5–9

5–5

FIRING BLOCK ASSEMBLY AND FOLLOWER ASSEMBLY

This task covers:

a.

Disassembly

b.

Assembly

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

Spanner wrench (item 17, Appx H)

Materials/Parts

Spring pin (item 6.1, Appx G)

Spring pin (item 5, Appx G)

Equipment Condition

Firing block assembly removed (TM 9–2350–311–10)

a.

Disassembly

CAUTION

Firing pin is under pressure and will spring out when removed. Hold firing pin during disassembly to

prevent loss of parts.

1

Depress firing pin (1) and remove.

2

Remove lock pin (2) and spring (3).

3

Remove spring pin (4) and discard.

4

Remove knob (5), spring (6) and follower assembly (7) from firing block (8).

NOTE

Step 5 pertains to the M284 cannon only.

5

Remove spring pin (9), shoulder screw (10), and shaft roller (11) from follower shaft (12). Discard spring pin.

M284 CANNON CONFIGURATION

M185 CANNON CONFIGURATION

4

5

1

3

8

10

11

9

12

6

4

5

6

7

2

3

8

1

2

7