Bearing Shell Surface Inspection; Gear Inspection; Screwed Fitting Inspection - Lycoming TEO-540-C1A Maintenance Manual

CAUTION
NOTICE: Polishing undersize is preferable to grinding undersize because crankshafts that are
polished do not require re-nitriding.
If one bearing journal is polished to 0.003 in. or 0.006 in. undersize, all
corresponding journals must be polished to the same size.
If a bearing surface is scored, galled, or worn and polishing to either 0.003 in. or
0.006 in. undersize does not remove the condition, replace the crankshaft.
If, after the bearing journal is polished to 0.003 in., the bearing journal requires more
E.
polishing complete the following:
(1) Polish to 0.006 in. undersize.
(2) Fit with 0.006 in. bearing insert.
(3) Repeat for all like bearings.
If the actual undersize is greater than 0.006 in., replace the crankshaft.
F.

8. Bearing Shell Surface Inspection

NOTICE: Inspections in this section refer to reusable items that do not require replacement in
accordance with the latest revision of Service Bulletin No. SB-240. Be sure to record
any part replacement or corrective action in the engine logbook.
A. Examine all bearing saddle surfaces for scoring, galling, gouges, and wear. If any of these
conditions are found, identify and correct the cause.
B. Make sure that the clearance of each bearing agrees with the specification in the latest
revision of the Service Table of Limits - SSP-1776.
C. If a bearing does not conform to the specified limits in the latest revision of the Service Table
of Limit - SSP-1776, discard it and replace it with a new one.
D. Examine all journal surfaces for galling, scores, misalignment, and out-of-round condition.
Replace a scored, galled, misaligned, or out-of-round component.
E. Examine the shafts and pins for straightness.

9. Gear Inspection

A. Examine the involutes of the gear teeth for pitting and excessive wear.
B. If pit marks or wear are found, discard the gear and replace it with a new one.
C. Examine the bearing surfaces of all gears for deep scratches.
D. Remove minor abrasions with a fine abrasive cloth.

10. Screwed Fitting Inspection

A. Examine the condition of the threads on screwed fittings (threaded fastenings or plugs).
B. Remove small nicks and burrs with a small file, fine abrasive cloth, or stone.
C. If the part cannot be repaired by polishing it, discard it and replace it with a new one.
D. If the part has too much distortion, galling, or mutilation (caused by over-tightening or use of
an incorrect tool), replace it with a new part. Do not re-use a non-conforming part.
72-20
Page 152
DURING POLISHING, DO NOT ALLOW THE LATHE SPEED TO
EXCEED 150 RPM.
TEO-540-C1A Engine Maintenance Manual
TEO-540-C1A Engine Maintenance Manual
© 2018 Avco Corporation. All Rights Reserved
November 2018