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 689 of 828

TM 9–2350–311–20–2

Change 2

18–19

a.

Leveling Gun Trunnions

NOTE

•

All quadrant seats must be wiped clean before positioning gunner’s quadrant on them for taking

readings.

•

If cannon is not equipped with muzzle flats, use gun tube leveling fixture.

1

Bring cannon to zero elevation using M1A1 gunner’s quadrant (1) (end-for-end correction applied) on the flat

of the muzzle end of tube (2).

2

Place M1A1 gunner’s quadrant (1) with zero reading (end-for-end correction applied) on breech ring quad-

rant seats (3).

3

Level gun trunnions by traversing cab left or right until bubble (4) is centered.

2

3

4

1

TOP SURFACE

BOTTOM SURFACE

1

1

GUN TUBE

LEVELING FIXTURE