TM-9-2320-280-10 HMMWV Operator Manual Download
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TM 9-2320-280-10 Change 1 2-105 2-8. GENERAL WARNING • The automatic transmissions on M998 and “A1” vehicles do not have a “PARK” position. Whenever the vehicle is parked, or the transmission in in “NEUTRAL”, the parking brake MUST BE APPLIED. Damage to equipment and injury to personnel may occur if these instructions are not followed. • The automatic transmissions on the M1123 and“A2” vehicles have a “PARK” position. Never use the transmission shift lever in place of the parking brake. Set the parking brake. Make sure the transmission shift lever is in the “P” (park) position and transfer case shift lever is NOT in the “N” (neutral) position. Damage to equipment and injury to personnel may occur if these instructions are not followed. • Chock blocks will be used when parking a vehicle with inopera- tive parking brakes, when operating in extreme cold conditions, when parking on inclines, or whenever and wherever maintenance is being performed. Failure to do so may result in injury to personnel or damage to equipment. • For M1097, M1123, and all A1 and A2 model vehicles only, hearing protection is required for driver and passengers when engine is running. Noise levels produced by these vehicles exceed 85 dBA, which may cause injury to personnel. Section III. OPERATION UNDER USUAL CONDITIONS This section provides instructions for vehicle operations under moderate temperature, humidity, and terrain conditions. For vehicle operation under unusual conditions, refer to section IV of this chapter. NOTE Before you operate your vehicle, be sure to perform the preventive maintenance checks and services shown in table 2-2. 2-9. BREAK-IN SERVICE 2-10. STARTING THE ENGINE a. Perform all before operation checks and services as indicated in table 2-2. b. Upon receipt of vehicle, or after engine replacement, the following break-in speeds and precautions should be observed during the first 500 miles (805 km) of operation: • Do not exceed a speed of 55 miles per hour (89 kilometers per hour). • Do not drive for long periods of time at constant speed. • Avoid rapid acceleration or deceleration. • Drive at a moderate speed until the engine is fully warmed up. • No trailer towing.