Suspension U-Bolt Torque Check
Notice: Failure to retorque the U-bolt nuts could result in spring breakage and abnormal tire wear.
Check the U-bolt torque of both the front/rear axles and suspension spring packs where applicable.
- Park the vehicle on a level surface and apply the parking brakes. Chock the tires.
- Check the U-bolt torque. See Table. or U-bolt torque
specifications. Tighten in a diagonal pattern as shown in Fig.. Set a click-type
torque wrench to the mid-point torque value for the fastener being
checked. Turn the wrench in a clockwise motion (looking up) until
the torque wrench clicks, then release pressure on the torque wrench,
and turn the wrench again until it clicks. If the nut turns on the
second application, the bolt is stretching and must be replaced. See of the Western Star 47X
and 49X Workshop Manualfor bolt replacement procedures.
Fig. 1, Tightening Pattern for U-Bolt High Nuts
Table 1, Spring U-Bolt High Nut Torque Values
Spring U-Bolt High Nut Torque Values1 Size Torque: lbf·ft (N·m) 5/8–18
Stage 1: Hand-tighen Stage 2: 60 (81) Stage 3: 200 (271) Stage 4: 180 to 230 (245 to 313)
3/4–16
Stage 1: Hand-tighten Stage 2: 60 (81) Stage 3: 200 (271) Stage 4: 270 to 330 (367 to 449)
7/8–14
Stage 1: Hand-tighten Stage 2: 60 (81) Stage 3: 200 (271) Stage 4: 420–500 (571 to 680)
1–14
Stage 1: Hand-tighen Stage 2: 60 (81) Stage 3: 200 (271) Stage 4: 520–600 (707 to 816)
M20-1.5
Stage 1 : Hand tighten Stage 2: 60 (81) Stage 3 : 200 (271) Stage 4 : 268–329 (364 to 446)
Table 1, Spring U-Bolt High Nut Torque Values