The following procedures are for 2wd only. For wheel bearing procedures on 4wd vehicles, please refer to the Front Drive Axle section in Drive Train in this repair guide.
ADJUSTMENT AND LUBRICATION
See Figures 1, 2, 3 and 4
Only the front wheel bearings require periodic service. The lubricant to use is high temperature disc brake wheel bearing grease meeting NLGI No. 2 specifications. (This grease should be used even if the truck is equipped with drum brakes; it has superior protection characteristics.) 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:
- Remove all outside dirt from the housing before exposing the bearing.
- Treat a used bearing as gently as you would a new one.
- Work with clean tools in clean surroundings.
- Use clean, dry canvas gloves, or at least clean, dry hands.
- Clean solvents and flushing fluids are a must.
- Use clean paper when laying out the bearings to dry.
- Protect disassembled bearings from rust and dirt. Cover them up.
- Use clean rags to wipe bearings
- Keep the bearings in oil-proof paper when they are to be stored or are not in use.
- Clean the inside of the housing before replacing the bearings.
- Don't work in dirty surroundings.
- Don't use dirty, chipped, or damaged tools.
- Try not to work on wooden work benches or use wooden mallets.
- Don't handle bearings with dirty or moist hands.
- Do not use gasoline for cleaning; use a safe solvent.
- Do not spin dry bearings with compressed air. They will be damaged.
- Do not spin unclean bearings.
- Avoid using cotton waste or dirty cloths to wipe bearings.
- Try not to scratch or nick bearing surfaces.
- Do not allow the bearing to come in contact with dirt or rust at any time.
If your truck has drum brakes you will need a special claw type puller to remove the inner bearing and the steering knuckle grease retainer.
Procedures are basically the same for either disc or drum brakes.
- Remove the bake drum or brake caliper, following the procedure outlined in Brakes of this repair guide.
- It is not necessary to remove the drum or disc from the hub. The outer wheel bearing will come off with the hub. Simply pull the hub and disc or drum assembly towards you off the spindle. Be sure to catch the bearing before it falls to the ground.
- Drum brakes: The inner bearing and grease retainer must be pulled from the spindle with the claw puller. Be sure that the fingers of the tool pull on the seal, and not on the bearing itself. Discard the grease retainer.
Disc brakes: The inner bearing will have to be driven from the hub along with the oil seal. Use a brass rod as a drift and carefully drive the inner bearing cone 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 in the races 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.
- You can use a brass rod as a drift, or a large socket or piece of pipe to drive the inner and outer bearing cups out of the hub.
- Install the new inner cup, and then the outer cup, in that order, into the hub, using either the brass drift or socket method outlined earlier.
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.
- Drum brakes: Press a new grease retainer onto the spindle. 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. Press the inner bearing into the spindle, seating it firmly against the grease retainer.
Disc brakes: Coat the inner bearing cup with grease. Pack the inner bearing with grease as outlined for drum brakes, and press the inner bearing into the cup. Press a new oil seal into place on top of the bearing. You may have to give the seal a few gentle raps with a soft drift to get it to seat properly.
- Install the hub and drum or disc assembly onto the spindle. With drum brakes, first thoroughly coat the inner cup with grease.
- 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 replaced last, after the preload adjustment. You can put the grease away now.
- Install the lock washer, and castellated nut (lock washer, nut, and adjusting castle nut with disc brakes) loosely, and proceed to the preload adjustment following.
- While turning the hub forward, tighten the castellated nut (plain nut on disc brakes) to 25-29 ft. lbs. (34-39 Nm).
- Rotate the hub a few more times to snug down the bearings.
- Retighten the nut to the above specification. Unscrew it 1 / 6 of a turn and lock it in place with a new cotter pin. On disc brakes, snug the adjusting nut up against the washer and then back it off the required distance to insert a new cotter pin. You should not have to back it off more than 1 / 6 of a turn.
- Install the grease cap, and wipe off any grease that oozes out.
- Install the front wheel and a couple of lug nuts. Check the axial play of the wheel by shaking it back and forth; the bearing freeplay should feel close to zero, but the wheel should spin freely. With drum brakes, be sure that the shoes are not dragging against the drum.
- If the bearing play is correct with drum brakes you can install the rest of the lug nuts. With disc brakes, remove the wheel, replace the caliper, then install the wheel.
For wheel bearing procedures on 4wd vehicles, please refer to the Front Drive Axle section in Drive Train in this repair guide.