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 115 of 828

TM 9–2350–311–20–2

3–6

Change 2

3–3

TROUBLESHOOTING CHART — CONTINUED

a.

BREECH MECHANISM — CONTINUED

(1)

BREECH DOES NOT OPEN MANUALLY.

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

Spanner wrench (item 17, Appx H)

References

TM 9–2350–311–10

Notify support

maintenance.

1.

Slide firing group block to the right OPEN

position.

2.

Disengage plunger assembly from obturator

spindle nut (para 5–7).

3.

Check obturator spindle nut for looseness.

Is obturator spindle nut loose?

Go to step D.

yes

no

Check the operating handle plunger and

operating handle clutch for proper operation

(TM 9–2350–311–10).

Do they operate properly?

yes

no

A

B

CONTINUED ON NEXT PAGE

C

1.

Tighten obturator spindle nut using spanner

wrench.

2.

Engage plunger assembly with obturator spindle

nut (para 5–7).

3.

Attempt to open breech.

Does breech open?

OPERATING

HANDLE

CLUTCH

OPERATING HANDLE PLUNGER

PLUNGER

ASSEMBLY

OBTURATOR

SPINDLE

NUT

FIRING

GROUP

BLOCK