TM-9-2320-280-10 HMMWV Operator Manual Download
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TM 9-2320-280-10 2-142 Change 1 2-33. OPERATING IN MUD a. Before Operation. (1) Before operating in mud, place transfer case shift lever in “H/L” (high lock range) and transmission shift lever in “D” (drive) (or “ ” (overdrive) for M1123 and A2 vehicles). (2) Refer to paragraph 2-29 for techniques that can be used when operating on unusual terrain. b. During Operation. CAUTION • Do not repeatedly shift transmission or overspeed the engine during operation in deep mud. Damage to drivetrain may result. • Use wrecker or a second vehicle equipped with winch to recover vehicles mired in deep mud. Do not attempt to “rock” vehicles out of deep mud with quick transmission shift changes. Damage to transmission will occur. NOTE If additional power is needed to extract vehicle when mired in mud, place transmission in “1” (first) and transfer case in “L” (low range). After vehicle is extracted from mired condition, immediately return transfer case to “H/L” (high lock range) position. Skidding and sudden loss of steering control are operating problems in mud. When rear end skidding occurs, immediately turn wheel in direction of skid. c. After Operation. (1) Wash the following as soon as possible with low pressure water: CAUTION Do not allow water to enter air intake cap or air cleaner assembly. Damage to engine will occur. (a) Radiator and oil cooler (b) Propeller shaft U-joint and halfshafts (c) Steering linkage and ball joints WARNING Do not rely on service brakes until they dry out. Keep applying brakes until uneven braking ceases. Failure to do this may cause damage to vehicle and injury or death to personnel. (d) Brake rotors and pads (service) (e) Brake rotors and pads (park) (f) Parking brake linkage (g) Service lights (h) Transmission control linkage (i) Accelerator control linkage (j) Sway bar bushings (k) Towing pintle (l) Fuel filler cap (m) Vehicle exterior (n) Geared hubs (o) Advance solenoid rocker arm and fuel injection pump D