TB 1-1520-238-30-19
NOTE
The bearing bore may show slight wear and scoring from being pressed on
and off and should not be rejected for this.
8.12 Annular ball bearing (25) inspection. If annular ball bearing (25) is considered visually acceptable, then
the annular ball bearing can be re-greased IAW paragraph 9. Serviceable, well lubricated bearings feel
smooth when rotated with no perceptible roughness, catching, or binding. Corrosion should not be evident
on the bearing exterior. If any of the below conditions exist, reject the bearing and replace with a new one.
If the inspection determines that the bearing must be replaced, tag the bearing with an unserviceable tag,
place bearing in a plastic bag, and mark the bearing S/N, clutch S/N, and clutch TSO on it. Provide the bearing
to a Boeing CFSR, AMCOM LAR, or put the bearing in a shipping container for any clutch being returned.
8.12.1 Fractured Components. Cracked or broken rings, retainers or rolling elements.
8.12.2 Frozen or seized bearings. Reject bearings that are frozen and cannot be rotated.
8.12.3 Rough Bearings. Reject any bearings that has any obvious catching or binding when turned by hand.
Roughness can be caused by caking or deteriorated grease, foreign particles, corrosion, brinelling from
improper installation, or spalling of the raceways or rolling elements.
8.12.4 Heat discolored bearings. Discoloration (bluing or a straw color) of the exterior of the bearings
usually indicates overheating. If any discoloration is found reject clutch assembly, reassemble and return to
supply for disposition.
8.12.5 Corroded bearings. External corrosion frequently indicates that the interior may also be corroded.
Reject bearings with corrosion.
8.13 Inspect seal (18) and seal (22) for nicks, dents, and gouges, none allowed. Seal shall be uniform and
smooth.
9.1 General Requirements.
9.2 Handling Bearings Prior to Regreasing.
9.2.1 Protection. Bearings received from the clutch disassembly are unprotected and must be given
immediate protection. The fact cannot be overemphasized that many bearings are contaminated prior to
lubrication or preservation, and must be rejected later. Every precaution shall be taken to keep all bearings
surfaces free of foreign material contamination during all phases of the process.
9.3 Handling of Lubricants. It is imperative that lubricants used in rolling bearings are kept clean, and every
precaution shall be taken to prevent the contamination of lubricants with foreign materials.
9.4 Lubricating Bearings with Grease.
9.4.1 Under Lubrication. Insufficient amounts of grease will cause premature bearing failure. The oil
component of the grease is insufficient and higher operating temperatures and internal wear of the bearing
will result.
9.4.2 Over-Lubrication. Excessive quantities of grease causes churning within the bearing with subsequent
temperature and volume rise. This is particularly true of the bearings running at high speeds where churning
of the lubricant will cause the bearing to run excessively hot.
9.4.3 Excess greases will be thrown out of the bearing causing contamination or malfunction of other
components. Early deterioration of the grease, with possible premature bearing failure, is also a result of
overlubrication.
9.4.4 Contaminated Grease. Although the amount of grease put into a bearing is of vital importance, the
condition of the grease is just as important.
9.5 Clean dust free synthetic gloves shall be used throughout this procedure.
9.6 Calculate replenishment grease weight. Use Regreasing Procedure Worksheet. (Figure 8).
A =___________________ Weight of Bearing
T = 481 A =___________________ Total Weight of Grease Required
F = T / 2 =___________________ Weight of Grease Required Each Row
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