Table 2-1.  Unit Level Preventive Maintenance Checks and Services HMMWV (Cont'd) ITEM NO. INTERVAL ITEM TO BE INSPECTED PROCEDURES 16 Semi- Driveline i.  Tighten halfshaft mounting bolts to i.  Loose, missing, or Annual Compo- 48 lb-ft (65 N•m). broken bolts. nents (Cont’d) 17 Semi- Exhaust Inspect for cracked and loose pipes, Cracked, loose, or holes in Annual Compo- muffler, and hangers. Check for ex- pipes or muffler. nents haust leaks. Exhaust leak. 18 Semi- Frame and a.  Inspect frame side rails for cracks, a.  Any loose or missing Annual Cross- breaks, bends, wear, deterioration, fasteners. Cracks, bends, members and missing or loose fasteners. or breaks in frame. b.  Inspect crossmembers for cracks, b.  Any loose or missing breaks, bends, deterioration, and fasteners. Cracks, bends, loose or missing fasteners. or breaks in cross- members. c.  Inspect for missing, broken, bent, c.  Any missing, broken, or loose bumper supports before bent, or loose bumper towing a trailer. supports. 19 Semi- Tires Annual a.  Check tread depth of tires with tire a.  Tread depth is less gauge. If tread depth is less than 2/32 than 2/32 in. (1.59 mm). in. (1.59 mm), replace tire in approx- imately 400 miles (644 km) bias tires will wear 1/32 in. (0.79 mm), radial tires will take approximately 1,300 miles (2092 km) to wear 1/32 in. (0.79 mm). If mission will require the vehicle to travel this distance within a month, replace tire if it measures 3/32 in. (2.38 mm). TM 9-2320-280-20-1 Change 1 2-19 NOT FULLY MISSION CAPABLE IF: WARNING •  Changing tire pressures or wheel alignment, out of the recommended specification, may adversely affect the vehicle's handling characteristics. Loss of vehicle control may result in serious injury or death and damage to equipment. •  Radial and bias ply tires should not be mixed on the same vehicle. Injury to personnel and damage to equipment may result. NOTE Vehicle must be up on jack stands for the following checks.