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 481 of 775

TM 9-2350-311-10

3-6 ARMAMENT AND CAB MAINTENANCE — CONTINUED

3-6.8

Breech Mechanism —Continued

c. Assembly — Continued

21

22

23

NOTE

Adjuster may have lugs for an adjustable wrench or holes for a spanner wrench.

Apply pre-load tension on breech mechanism closing springs. Use adjustable wrench or spanner wrench

installed in holes of adjuster (7). The three notches in the adjuster provide the three graduations of

adjustment. Do not apply more pre-load than is necessary to close breechblock (9) securely. Use of the

final (third) notch reduces life of the leaf springs and should be used only if necessary.

NOTE

• Step 22 requires two people.

• If stop plate has an arrow on it, be sure it points to muzzle brake end.

Depress plunger (3) with punch, and apply pressure to stop plate (5) and rack springs (6) with wood

hammer handle. Slide rack plate (4) over stop plate.

Slide rack plate (4) forward until rear hole of rack plate engages plunger (3).

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