Inspection of the Driveline
- Park the vehicle on a flat, level surface, apply the parking brakes, and chock the tires.
- Check the torque of the U-joint 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..
Note: Tighten the capscrews in a counterclockwise sequence, starting with either number 1 position.
Fig. 1, Tightening Sequence, Half-Round Yoke Bearing Strap Capscrews
Table 1, U-Joint Capscrew Torque Specifications
U-Joint Capscrew Torque Specifications
Yoke
Capscrew Size
Torque: lbf·ft (N·m)
0.375"
45–60 (60–80)
0.5"
115–135 (155–183)
12 mm
115–135 (155–183)
0.375"
38–48 (52–65)
0.5"
115-135 (155-183)
Table 1, U-Joint Capscrew Torque Specifications
- 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 of the 108SD and 114SD 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.
Note: Not all fasteners are shown.
-
Transmission
-
Transmission Output-Shaft End-Yoke (half-round)
-
U-Joint Assembly
-
Bearing Plate Self-Locking Capscrew
-
Bearing Cup (for full-round yoke)
-
U-Joint Cross
-
Bearing Cup (for half-round yoke)
-
Bearing Strap and Bearing-Strap Capscrew
-
Slip-Joint Assembly
-
Sleeve-Yoke (full-round)
-
Dust Cap
-
Splined Stub Shaft
-
Driveshaft Tube
-
Tube-Yoke (full-round)
-
Axle Input-Shaft End-Yoke (half-round)
-
Rear Axle
Fig. 2, Components of a Basic Driveline
-
- 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.
- 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 Section 41.00, Specifications 400 of the 108SD and 114SD Workshop Manual for torque specifications. Replace the midship bearing assembly if the rubber cushion is deteriorated or oil-soaked.
- 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.
- Examine the driveshaft tubes for dents, bends, twists, or other damage. If any tube appears to be damaged, refer to of the 108SD and 114SD Workshop Manual for repair and replacement instructions.
- 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.
- For driveshafts with slip joints, check to be sure the
yoke plug is not loose or missing; see Fig., item 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.
Warning: Self-locking bearing-cup or bearing-strap capscrews must not be reused; replace the capscrews with new ones. Also, do not undertighten or overtighten any bearing-cup or bearing-strap capscrews. A loose or broken fastener at any point in the driveline weakens the driveline connection, which could cause serious vehicle damage, or could result in a driveshaft separating from the vehicle, possibly causing loss of vehicle control that could result in serious personal injury or death.