TM-9-2350-311-10

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

TECHNICAL MANUAL; OPERATOR’S MANUAL

NOVEMBER 1994

TM-9-2350-311-10 - Page 483 of 775

TM 9--2350--311--10

Change 6

3--79

3--6

ARMAMENT AND CAB MAINTENANCE — CONTINUED

3--6.8

Breech Mechanism — Continued

c. Assembly — Continued

NOTE

Step 25 applies to M49 firing mechanism on M109A5 M284 cannon assembly.

25

Assemble M49 firing mechanism.

(a)

Install firing hammer (66) in access cover (67).

(b)

Install hammer guide yoke (56) on firing hammer (66) so groove in firing hammer lines up with

holes in hammer guide yoke.

NOTE

Apply grease (item 17, Appx D) to holes in hammer guide yoke prior to installing bearing balls.

(c)

Install spring (64) and sleeve bushing (63) on hammer guide yoke (56) and install three bearing

balls (65) into hammer guide yoke holes between spring coils. Slide sleeve bushing against spring

until spring is fully compressed against access cover (67).

(d)

Pull firing hammer (66) from hammer guide yoke (56) until sleeve bushing (63) locks in place.

NOTE

Use a 1--1/8 inch (2.86 cm) socket and M34 or M18 fuzesetter to complete assembly.

(e)

Set yoke and hammer group (76) on socket so firing hammer (66) hangs freely.

66

67

56

64

63

65

76