Introduction: How to Change a Wheel Bearing
Replacing a wheel bearing is similar to brain surgery in one aspect; if you don't work clean you will bury the patient. Any dirt or dust, which gets in to the bearing, will mix with the grease and form a grinding paste that will destroy it in a very short distance.
Slack off any brake connections and remove the wheel.
Remove the dust cap in the center of the brake drum and set aside. You will find some sort of castle nut locked by a split pin. Remove the split pin and loosen the nut. A lot of brake drums are secured by an additional phillips head screw, if so remove it.
If the brakes have been properly slacked off the brake drum should pull off, if not, a bit of gentle persuasion with a hammer to loosen it is in order.
Often the inner bearing and oil seal stays behind on the axle stub and have to be removed after the drum has been pulled off. Avoid getting any grease on the brake linings, this will extend their life but destroy their braking ability.
You will see that the bearings consist of two parts, the bearing with the rollers and the shell that they run in.
Remove the two bearing shells from the brake drum, note the direction of the taper on the inside of the shells, they should be tapering to the inside of the drum.
Clean the drum and axle properly removing all dirt and old grease.
Gently tap in the new bearing shells in a circular pattern taking care not to damage them.
Pack the new bearings with wheel bearing grease by putting a dollop on the palm of your hand and wiping it in between the rollers until it is full. Start with the inner bearing. Insert the inner bearing in to the shell and put some grease on the inside of the new oil seal. Gently tap the new seal in place. The reason for tapping in a circular pattern is to ensure the shells and oil seal go in evenly.
Lubricate the lip of the oil seal with some grease and slide the drum back on.
Fit the packed outer bearing and replace any washers that came out. Tighten the retaining nut until no more play is felt in the assembly. Turn a few times to seat and feel for play. I normally over tighten them slightly and back off about 1/8 turn.
Fit new split pin and replace dust cap. Reset brakes.
Replace wheel and go on holiday