The following procedures are for 2wd only. For wheel bearing procedures on 4wd vehicles, please refer toChapter 8.
ADJUSTMENT AND LUBRICATION
Only the front wheel bearings require periodic service (refer to the Maintenance Schedule for your vehicle). The recommended lubricant is high temperature disc brake wheel bearing grease meeting NLGI No. 2 specifications. This service is recommended at the specified period in the Maintenance Intervals chart, or whenever the truck has been driven in water up to the hub.
Before handling the bearings there are a few things that you should remember:Remember to DO the following:
Do NOT do the following:
- Remove the brake caliper, following the procedure outlined in Brakes .
- The outer wheel bearing will come off with the hub. Simply pull the hub/disc assembly towards you off the spindle. Be sure to catch the inner bearing before it falls to the ground.
- The inner bearing will have to be driven from the hub along with the oil seal. Use only a brass rod as a drift and carefully drive the inner bearing out. Remove the bearing and the oil seal. Discard the seal.
- Clean the bearings in solvent and allow to air dry. You risk leaving bits of lint if you dry them with a rag. Clean the bearing cups in the hub.
- Inspect the bearings carefully. If they are worn, pitted, burned, or scored, they should be replaced, along with the bearing cups in which they run.
- If necessary, drive the inner and outer bearings cups from the hub using a brass rod as a drift, or a large socket or piece of pipe.
- Install the new inner cup, and then the outer cup, into the hub using either the brass drift or a large socket.
Use care not to cock the bearing cups in the hub. If they are not fully seated, the bearings will be impossible to adjust properly.
- Place a large glob of grease into one palm and force the edge of the inner bearing into it so that the grease fills the bearing. Do this until the whole bearing is packed. Coat the inner bearing cup with grease. Install the inner bearing into the cup. Press a new oil seal into place on top of the hub assembly. You may have to give the seal a few gentle raps with a soft drift to get it to seat properly.
- Install the hub assembly onto the spindle.
- Coat the outer bearing cup with grease. Pack the outer bearing with grease and install into the cup.
- Pack the grease cap with grease and set it aside. It will be installed last, after the preload adjustment. You can put the grease away now.
- Install the lock washer, nut, and adjusting castle nut loosely, and go on to the preload adjustment.
See Figure 1
- While turning the hub forward, tighten the adjusting nut to 25-29 ft. lbs. (34-39 Nm).
- Rotate the hub in both directions a few times to seat the bearings.
- Retighten the nut to the above specification.
- Loosen the wheel bearing locknut 45 degrees. Fit the adjusting cap (castle nut) and a new cotter pin. Align the cotter pin slot by loosening the nut 15 degrees or less.
- Install the grease cap, and wipe off any grease that oozes out.
- Check the axial play of the wheel by shaking it back and forth; the bearing free-play should be close to zero, but the wheel should spin freely.
If you measure wheel bearing preload with a spring-type gauge, measure it at the wheel hub bolt, with the tire removed. The hub assembly (with new grease seal installed) should rotate with 2.2-6.4 lbs. (1-3 kg) of pressure.
- Install the brake caliper assembly.
For wheel bearing procedures on 4wd vehicles, please refer to Suspension & Steering of this repair guide.