Inspection of the Wheel and Tire

4700 d 23.01.002

Walk around the vehicle and visually inspect each wheel and tire assembly.

Important: Wheel covers decrease drag force as a vehicle moves, thereby improving fuel efficiency. If replacement of a wheel cover is necessary, the replacement cover must meet or exceed the drag reduction performance of the originally installed cover in order to maintain compliance with greenhouse gas and fuel efficiency regulations.

  1. If the vehicle was originally equipped with wheel covers, ensure all wheel covers are present. Inspect wheel covers for damage or wear. Remove wheel covers from rear drive wheels, if equipped, prior to inspecting the tires and wheel components.

    2. Note: During wheel cover installation, ensure the V-notch in the liner inner retaining ring is centered on the valve stem. The inner and outer retaining rings should be uniformly aligned to each other and to the wheel rim. The outer retaining ring of the liner is equipped with two canvas flaps. When installing the face cover, make sure the cover retaining ring is inserted between the two canvas flaps on the liner outer retaining ring so that the Velcro strips line up between the face cover and the liner. Make certain the detachable view cover is centered on the face cover, and the Velcro strips are pressed firmly in place.

  2. Inspect each tire for the following:

    • valve stem caps on every tire, screwed on finger-tight

    • bulges, cracks, cuts, and penetrations

    • oil contamination (petroleum derivatives will soften the rubber and destroy the tire)

    • tread depth—if tread is less than4/32inch (3 mm) on any front tire, or less than 2/32 inch (1.5 mm) on any rear tire, replace the tire

    • debris lodged between dual tire sets

    3. Important: Low-rolling resistance (LRR) tires minimize wasted energy as a tire rolls, thereby decreasing rolling effort and improving fuel efficiency. If tire replacement is necessary, replacement tires must meet or have less rolling resistance than the originally installed tires in order to maintain compliance with greenhouse gas and fuel efficiency regulations.

    Contact your tire manufacturer/supplier to determine the rolling resistance of the originally installed tires. Visitwww.epa.gov/smartwayfor additional information and resources.

  3. Check tire inflation.
    For inflation pressures and maximum loads, see the tire manufacturer's guidelines. Inflate the tires to the applicable pressures if needed.
    If a tire has been run flat or under-inflated, check the wheel and tire for damage before adding air.
    Keep compressed air reservoirs and lines dry during tire inflation. Use well-maintained inline moisture traps and service them regularly.

    4. Warning: Do not operate the vehicle with underinflated or overinflated tires. Incorrect inflation can stress the tires and make the tires and rims more susceptible to damage, possibly leading to rim or tire failure and loss of vehicle control, resulting in serious personal injury or death.

    Important: The load and cold inflation pressure must not exceed the rim or wheel manufacturer's recommendations, even though the tire may be approved for a higher load inflation. Consult the rim or wheel manufacturer for the correct tire inflation pressure for the vehicle load.

    Notice: A weekly pressure loss of 4 psi (28 kPa) or more in a tire may indicate damage. The tire should be inspected and, if necessary, repaired or replaced by a qualified tire service facility.

  4. Examine each rim and wheel component.
    1. Remove all dirt and debris from the assembly. Rust streaks or metal build-up around stud holes, or out-of-round or worn stud holes, may be caused by loose wheel nuts.

      2. Warning: Have any worn or damaged wheel components replaced by a qualified person using the wheel manufacturer's instructions and the wheel industry's standard safety precautions and equipment. Otherwise a vehicle or workshop accident could occur, possibly resulting in serious personal injury or death.

    2. Inspect for broken, cracked, badly worn, bent, rusty, or sprung rings and rims.

      3. Notice: Use the recommended torque values and follow the proper tightening sequence. Insufficient wheel nut torque can cause wheel shimmy, resulting in wheel damage, stud breakage, and extreme tire tread wear. Excessive wheel nut torque can break studs, damage threads, and crack discs in the stud hole area.

    3. Make sure all wheel nuts are tightened. If tightening is necessary, use the tightening pattern in Fig. to initially tighten the flange nuts to 50 to 100 lbf·ft (68 to 136 N·m). Then tighten the flange nuts to 450 to 500 lbf·ft (610 to 678 N·m).

      Fig. 1, Tightening Pattern, 10-Hole Wheels

  5. Inspect the outboard side of all wheel hubs and the hub oil seal area on the inboard side of each wheel for signs of oil leakage. If any oil is found on wheel and tire or brake components, remove the vehicle from service until the leak has been fixed.
    If needed, fill the hubs to the level indicated on the hub cap. See Group 35 of the Western Star Maintenance Manual for recommended lubricants.
  6. Check that mud flaps are undamaged and hang 10 inches (25.4 cm) or less from the ground.
Note:
Parent topic: Daily Pretrip Inspection and Maintenance
Document Number: 0000118803
Manual Publication Date: 2024-05-13
Topic Publication Date: 2024-05-16