Lippert Components Trailer Axle (8-12K) - Manual (Page 6)

Rev: 04.18.2014
Page 6
Trailer Axle 8-12K Owners Manual FULL
Brake Drum Inspection
The brake shoes contact the drum surface and the magnet contacts the armature. These surfaces are
subject to wear and should be inspected periodically.
The drum surface should be re-machined if wear is more than .030” or out of round by more than .015”. The
drum should be replaced if scoring or wear is greater than .090”.
The inner surface of the brake drum that contacts the brake magnet is the armature surface. If the armature
surface is scored or worn unevenly, it should not be machined more than .030”. The magnets should be
replaced whenever the armature surface is refaced and vice versa.
NOTE: Ensure that the wheel bearing cavities are clean and free of contamination before reinstalling
bearing and seals. Resurfacing procedures can produce metal chips and dust that can contaminate
the wheel bearings and cause failure.
Bearing Inspection
Wash all grease and oil from the bearing cone using a suitable solvent. Dry the bearing with a clean, lint-free
cloth and inspect each roller completely. If any pitting, spalling, or corrosion is present, then the bearing
must be replaced. The bearing cup inside the hub must be inspected.
NOTE: Bearings must always be replaced in sets of one cone and one cup.
Always wear eye protection when servicing the axle, brakes, hubs, springs and wheels. Failure to wear
eye protection may result in serious injury.
Follow the procedure below to replace the bearing cup:
1. Place hub on a flat surface with bearing cup on the bottom.
2. With brass drift punch, lightly tap around the small end of the cup to push it out.
3. Clean the hub bore. Replace the cup by tapping it back in with the brass drift punch. Cup should be
seated against the retaining shoulder in the hub.
NOTE: Consult Bearing Replacement Chart for proper replacement bearings.
NOTE: Replacing the bearing cup is a very precise process. The cup must be perfectly seated when
replaced. If the cup is not seated correctly, damage to the assembly may not be covered by the
warranty. Consult Lippert Components, Inc. prior to replacing bearing and bearing cup. The trailer
should be taken to a certified service center for this work to be done.
Do not mix Lithium, calcium, sodium or barium complex greases. Chemical compatibility problems may
occur. If you are changing from one chemical grease to another, be sure all old grease is removed prior to
applying new grease. If the old grease is not removed completely, chemical compatibility may result in
component failure or damage.
Drum Maximum Re-bore Diameter
12.25" 12.340"