8
Hubs, Drums and Bearings
HUBS, DRUMS AND BEARINGS
Rockwell American bearing configuration uses industry standards for-
bearing sets (bearings & cones) and hubs. This standard of using tapered
roller bearings helps to reduce the axial end play provided at assembly
and is essential to performance of the bearings life. The bearings are
packed with lithium base grease.
Your axles may be equipped with the Rockwell American Posi-lube
system which provides for lubricating the hubs at a special grease fit-
ting. This option allows grease to flow through specially machined axle
spindles, which have been drilled to allow the grease to be passed from
the fitting tothe inner bearing and back out through the outer bearing.
BRAKE DRUM INSPECTION
The brake drum surface should be inspected for scoring or excessive
wear. If the wear is greater than .020” oversized it should be resurfaced. If
the drum has worn out of round by more than .015” it should be re-ma-
chined.If wear or scoring is more than .090.” the hub and drum assembly
will have to be replaced.
The armature surface (which contacts the magnet) needs to be inspected
for uneven wear or scoring. Drums can be resurfaced removing no more
than .030” and should be to 120 micro inch finish. In the event you need
to turn the drums or resurface the armature it is recommended that you
replace the magnets at the same time.
Special notes
Make sure the inside of the hub cavity is carefully cleaned
•
and free of any contamination following turning and before re-
assembly.
