TM-9-2350-358-BD

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A6

TECHNICAL MANUAL; OPERATOR’S, UNIT, AND DIRECT SUPPORT SUPPORT MAINTENANCE

MARCH 1994

TM-9-2350-358-BD - Page 212 of 343

TM 9-2350-358-BD

SECTION V.

SPROCKET WHEEL

10-13. GENERAL

Sprocket wheels transmit both driving and braking forces from transmission to tracks.

Damage to sprocket wheels can

greatly reduce or eliminate howitzer’s mobility.

10-14. DRIVE SPROCKET BOLTS SHEARED OFF

General Information:

The final drive sprocket bolts can work loose allowing the sprocket to shift and shear part or all of the mounting bolts,

resulting in the track being thrown.

If new mounting bolts are not available the sprocket can be remounted by obtaining

bolts from the other side of the vehicle.

At least five of the ten mounting bolts must be installed.

If a sufficient number of

bolts are not available, the sprocket can be welded to the hub.

If the full amount of mounting bolts are not used, or the

sprocket is welded, pivot steer should not be used.

The side stress could cause the bolts or weld to shear.

The vehicle

cannot operate when a drive sprocket has sustained substantial damage.

Sprockets with one or several non-consecutive

teeth missing can operate at reduced speeds.

Option 1:

Limitations:

If welded, reduced mobility.

Personnel/Time Required:

•

2 soldiers

•

1.0-2.0 hours

Materials/Tools:

•

Replacement sprocket bolts, nuts (scavenged from available source)

•

Welding equipment

•

Lift capability

References:

TM 9-2350-314-20-1-2

Procedural Steps:

1.

Separate track to allow access to drive sprocket assembly.

10-14