TM-9-2350-358-BD M109A6 Battlefield Damage Assessment and Repair Download
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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