Driveline Inspection

122SD mm 41.01.01
  1. Park the vehicle on a flat, level surface, apply the parking brakes, and chock the tires.
  2. Check the torque of the bearing-cup or bearing-strap capscrews; see Table. for installed torque values. Remove and discard any loose capscrews. Do not reuse any loosened self-locking capscrews; they are designed for one-time installation only. Replace all loosened and removed capscrews with new ones. Tighten the new capscrews as specified in Table.. For half-round yokes with bearing straps , tighten the bearing-strap capscrews following the tightening sequence shown in Fig., in increments of 20 lbf·ft (25 N·m) to the torque specifications listed in Table..

    Table 1, Bearing Cap or Bearing Strap Capscrew Torque Specifications

    Bearing Cap or Bearing Strap Capscrew Torque Specifications

    U-Joint Type

    Torque: lbf·ft (N·m)

    Half-Round Yokes with Bearing Straps and 3/8-inch Capscrews (Fig., Ref. 8)

    45–60 (60–80)

    Half-Round Yokes with Bearing Straps and 1/2-inch Capscrews (Fig., Ref. 8)

    130–135 (175–185)

    Full-Round Yokes with Bearing Cups (Fig.)

    43 (58)

    RPL Series U-Joints with Bearing Cups (Fig.)

    125 (169)

      Table 1, Bearing Cap or Bearing Strap Capscrew Torque Specifications

      Tighten the capscrews in a counterclockwise sequence, starting with either number 1 position.

      Fig. 1, Tightening Sequence, Half-Round Yoke Bearing Strap Capscrews

      Note: Not all fasteners are shown.

      1. Transmission

      2. Transmission Output-Shaft End-Yoke (half-round)

      3. U-Joint Assembly

      4. Bearing Plate Self-Locking Capscrew

      5. Bearing Cup (for full-round yoke)

      6. U-Joint Cross

      7. Bearing Cup (for half-round yoke)

      8. Bearing Strap and Bearing-Strap Capscrew

      9. Slip-Joint Assembly

      10. Sleeve-Yoke (full-round)

      11. Dust Cap

      12. Splined Stub Shaft

      13. Driveshaft Tube

      14. Tube-Yoke (full-round)

      15. Axle Input-Shaft End-Yoke (half-round)

      16. Rear Axle

      Fig. 2, Components of a Basic Driveline

      1. Self-Locking Capscrew

      2. Adhesive Band

      Fig. 3, Meritor U-Joint Fasteners for Full-Round Yokes

      Fig. 4, Meritor RPL Series U-Joint

    1. Check the driveline yokes for cracks, and check end-yokes for looseness; see Fig.. Replace cracked yokes. If any end-yoke can be moved in or out on its shaft, or can be rocked on its shaft, disconnect the driveshaft and U-joint from the yoke, then check the drive component's shaft seal for leakage or other visible damage that may have been caused by the loose yoke. Replace the seal if needed, then tighten the yoke nut. Refer to Group 41, Specifications 400 of the 122SD and Coronado Workshop Manual for torque specifications. If the yoke is still loose after tightening the yoke nut, replace the end-yoke and yoke nut. Replace the prevailing torque locknut (end-yoke nut) if it was removed for yoke replacement, seal replacement, or any other reason.
    2. Check U-joint assemblies for wear by moving the driveshaft up and down, and from side to side. If any movement of the U-joint cross in the bearings can be felt or seen, replace the U-joint assembly.
    3. Check if the midship bearing and mounting are loose or have deteriorated, by attempting to move the driveshaft up and down, and from side to side. If the bearing is loose on its shaft, or rattles, replace it. If the bearing mount is loose on the frame, tighten the mounting fasteners to the proper torque value. See Group 41, Specifications 400 of the 122SD and Coronado Workshop Manual for torque specifications. Replace the midship bearing assembly if the rubber cushion is deteriorated or oil-soaked.
    4. Check slip joints for spline wear by moving the sleeve-yoke and splined shaft back and forth; see Fig.. If the slip joint can be twisted in a clockwise, or counterclockwise movement greater than 0.007 inch (0.18 mm), replace both the sleeve-yoke and the splined shaft.

      Attempt to move the sleeve-yoke and splined shaft back and forth.

      Fig. 5, Slip Joint Spline Wear Checking

    5. Examine the driveshaft tubes for dents, bends, twists, or other damage. If any tube appears to be damaged, refer to Group 41 of the 122SD and Coronado Workshop Manual for repair and replacement instructions.
    6. Examine the driveshaft for evidence of missing balance weights, and for build-up of foreign material. Remove any foreign material. If there is any evidence that balance weights are missing, remove the driveshaft and have it balanced.
    7. For driveshafts with slip joints, check to be sure the yoke plug is not loose or missing; see Fig., Ref. 2. Repair or replace the yoke plug as needed. If the yoke plug is missing, the splined shaft may be hitting the plug and knocking it out; contact your Regional Service Office for assistance in determining the correct driveshaft length.

      Fig. 6, Joint and U-Joint Lubrication

    Note:
    Parent topic: Driveline
    Document Number: 0000125954
    Manual Publication Date: 2025-02-11
    Topic Publication Date: 2024-06-21