Crankcase Maintenance; Exterior Crankcase Inspection - Lycoming TEO-540-C1A Maintenance Manual

TEO-540-C1A Engine Maintenance Manual
TEO-540-C1A Engine Maintenance Manual
72-20 - RECIPROCATING ENGINE – CRANKCASE MAINTENANCE

1. Exterior Crankcase Inspection

A. The exterior inspection of both crankcase halves is done to:
• Identify any oil leaks, cracks, and mechanical damage on the crankcase
• Make sure that hardware fasteners are torqued correctly
WARNING IF A DAMAGED OR CRACKED CRANKCASE IS NOT REPLACED, OIL
B. Examine the external surface of both crankcase halves. If any of the following are found,
replace both crankcase halves:
• Any raised metal on surfaces
• Any scratch, ding, dent, or, pit that exceeds 0.050 in. (1.27 mm) depth
• Any crack
NOTICE: Even if one crankcase half is worn, damaged, or cracked, replace both crankcase
halves as a matched set.
C. Examine the crankcase breather fitting for cracks, dents, and damage. If cracks, dents or
damage are found, replace the breather fitting.
CAUTION
D. Examine hold-down nuts on the cylinder head for looseness or damage. Replace loose or
damaged nuts or studs.
NOTICE: In the next step, do not use a torque tool (to prevent over-torque) during the check
for loose crankcase thru-bolts.
E. Examine the crankcase hardware fasteners for looseness or damage.
F. Replace any crankcase hardware fastener that is distorted, has corrosion or stripped threads
and torque per instructions in this chapter.
G. Examine the crankshaft oil seal for leakage or damage. Replace a leaking or damaged oil
seal.
NOTICE: To replace a leaking or damaged crankshaft oil seal with the engine assembled refer
to instructions in the latest revision of Service Instruction No. SI-1324.
© 2018 Avco Corporation. All Rights Reserved
November 2018
CAN LEAK OUT OF THE CRANKCASE AND CAUSE ENGINE
DAMAGE. DO NOT TRY TO WELD OR REPAIR A CRACKED
CRANKCASE. REPLACE BOTH CRANKCASE HALVES AS A
MATCHED SET EVEN IF ONLY ONE CRANKCASE HALF IS
DAMAGED OR CRACKED.
LOOSE CYLINDER BASE NUTS ON THE THRU-STUDS ARE AN
INDICATION THAT THERE IS NOT A UNIFORM LOAD ON THE MAIN
BEARINGS IN THE CRANKCASE. ENGINE DAMAGE CAN OCCUR.
DISASSEMBLE THE ENGINE PER INSTRUCTIONS IN THIS CHAPTER
TO IDENTIFY DAMAGE.
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