TM-9-2350-311-34-2 Maintenance Manual for Volume 2 M109 Cab Download
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TM 9-2350-311-34-2 c. CAB TRAVERSING SYSTEM The cab traversing system consists of the gunner’s selector switch box assembly, hydraulic motor, bypass valve assembly and solenoid, clutch mechanism, and gunner’s control handle. The M109A4/M109A5 howitzers have an additional clutch valve. The gunner’s selector switch box assembly is used to electrically switch the cab traversing mechanism between power and manual traversing. The bypass valve assembly and solenoid combination controls the hydraulic power between the manual and power modes. In the power mode, the solenoid will push out the plunger to divert the hydraulic fluid to the hydraulic motor. In the manual mode, the plunger will retract and disengage the hydraulic motor. The clutch mechanism controls the mechanical switching between the two modes and is controlled electrically (M109A2/M109A3 howitzers) or hydraulically (M109A4/M109A5 howitzers). The clutch valve in the M109A4/M109A5 howitzers controls the flow to the clutch. The gunner’s control handle operates the power traversing of the cab and the handwheel assembly operates the manual traversing of the cab. 2-35