Ball Bearing, Needle Bearing, and Oil Seal
Ball and Needle Bearing Wear Inspection
Do not remove the ball bearings for inspection. Re-
moval may damage them.
Check the ball bearings.
Since the ball bearings are made to extremely close toler-
ances, the wear must be judged by feel rather than mea-
surement. Clean each bearing in high flash-point solvent,
dry it (do not spin the bearing while it is dry), and oil it with
Spin [A] the bearing by hand to check its condition.
If the bearing is noisy, does not spin smoothly, or has any
rough spots, replace it.
Check the needle bearings.
The rollers in a needle bearing normally wear very little,
and wear is difficult to measure. Instead of measuring,
inspect the bearing for abrasion, color change, or other
If there is any doubt as to the condition of a needle bear-
ing, replace it.
Oil Seal Inspection
Inspect the oil seal.
Replace it if the lips are misshapen, discolored (indicating
that the rubber has deteriorated), hardened or otherwise