HDD 205 - Heavy Duty Diesel Suspension and Steering

Credits: 4
Instructional Contact Hours: 6

    A.        Steering Column
             1.   Identify causes of fixed and driver adjustable steering column and shaft noise, looseness, and binding problems; determine needed action.

             2.   Inspect and service steering shaft U-joint(s), slip joints, bearings, bushings, and seals; phase shaft.

             3.   Check cab mounting and adjust ride height.

             4.   Remove the steering wheel (includes steering wheels equipped with electrical/electronic controls and components); install and center the steering wheel.  Inspect, test, replace and calibrate steering angle sensor.

             5.   Disable and enable supplemental restraint system (SRS) in accordance with manufacturers' procedures.

    B.        Steering Units
             1.   Identify causes of power steering system noise, steering binding, darting/oversteer, reduced wheel cut, steering wheel kick, pulling, non- recovery, turning effort, looseness, hard steering, overheating, fluid leakage, and fluid aeration problems; determine needed action.

             2.   Determine recommended type of power steering fluid; check level and condition; determine needed action.

             3.   Flush and refill power steering system; purge air from system.

             4.   Perform power steering system pressure, temperature, and flow tests; determine needed action.

             5.   Inspect, service, or replace power steering reservoir including filter, seals, and gaskets.

             6.   Inspect power steering pump drive gear and coupling; replace as needed.

             7.   Inspect, adjust, or replace power steering pump, mountings, and brackets.

             8.   Inspect and replace power steering system cooler, lines, hoses, clamps/mountings, hose routings, and fittings.

             9.   Inspect, adjust, repair, or replace integral type power steering gear(s) (single and/or dual) and mountings.

    C.        Steering Linkage
             1.   Inspect and align pitman arm; replace as needed.

             2.       Check and adjust steering (wheel) stops; verify relief pressures.

             3.       Inspect and lubricate steering components.

2.         Complete NATEF tasks related to heavy duty diesel Suspension Systems as listed below.

    A.        Inspect front axles and attaching hardware; determine needed action.

    B.        Inspect and service kingpins, steering knuckle bushings, locks, bearings, seals, and covers; determine needed action.

    C.        Inspect shock absorbers, bushings, brackets, and mounts; replace as needed.

    D.        Inspect leaf springs, center bolts, clips, pins and bushings, shackles, U- bolts, insulators, brackets, and mounts; determine needed action.

    E.        Inspect axle aligning devices such as radius rods, track bars, stabilizer bars, torque arms, related bushings, mounts, shims, and cams; determine needed action.

    F.         Inspect tandem suspension equalizer components; determine needed action.

    G.        Inspect and test air suspension pressure regulator and height control valves, lines, hoses, dump valves, and fittings; adjust, repair or replace as needed.

    H.        Inspect air springs, mounting plates, springs, suspension arms, and bushings; replace as needed.

    I.          Measure and adjust ride height; determine needed action.

    J.          Identify rough ride problems; determine needed action.

3.         Complete NATEF tasks related to heavy duty diesel Wheel Alignment Diagnosis, Adjustment, and Repair as listed below.

    A.        Identify causes of vehicle wandering, pulling, shimmy, hard steering, and off-center steering wheel problems; adjust or repair as needed.

    B.        Check camber; determine needed action.

    C.        Check caster; adjust as needed.

    D.        Check and adjust toe settings.

    E.        Check rear axle(s) alignment (thrustline/centerline) and tracking; adjust or repair as needed.

    F.         Identify turning/Ackerman angle (toe-out-on-turns) problems; determine needed action.

    G.        Check front axle alignment (centerline); adjust or repair as needed.

4.         Complete NATEF tasks related to heavy duty diesel Wheels and Tires as listed below.

   A.          Identify tire wear patterns; check tread depth and pressure determine needed action.

    B.         Identify wheel/tire vibration, shimmy, pounding, hop (tramp) problems; determine needed action.

    C.        Remove and install steering and drive axle wheel/tire assemblies; torque mounting hardware to specifications with torque wrench.

    D.        Inspect tire for proper application, (size, load range, position, and tread design); determine needed action.

    E.        Inspect wheel/rims for proper application, hand hold alignment, load range, size, and design; determine needed action.

    F.         Check operation of tire pressure monitoring system (TPMS); determine needed action if applicable.

5.         Complete NATEF tasks related to heavy duty diesel Frame and Coupling Devices as listed below.

    A.         Inspect, service, and/or adjust fifth wheel, pivot pins, bushings, locking mechanisms, and mounting hardware.

    B.         Inspect and service sliding fifth wheel, tracks, stops, locking systems, air cylinders, springs, lines, hoses, and controls

    C.         Inspect frame and frame members for cracks, breaks, corrosion, distortion, elongated holes, looseness, and damage; determine needed repairs.

    D.        Inspect, install, or repair frame hangers, brackets, and cross members in accordance with manufacturers’ recommended procedures.

    E.            Inspect, repair, or replace pintle hooks and draw bars, if applicable.