Lycoming TEO-540-C1A Maintenance Manual page 177

TEO-540-C1A Engine Maintenance Manual
TEO-540-C1A Engine Maintenance Manual
Crankshaft Inspection Checklist for TEO-540-C1A Engines (Cont.)
Item
Criteria for Crankshaft Trigger Gear Assembly Replacement
Lycoming Engines no longer approves rework or repair of an unacceptable crankshaft trigger gear
assembly. Replace the crankshaft trigger gear assembly with a serviceable crankshaft trigger gear
assembly if any of the following are found during the crankshaft trigger gear assembly identification
and inspection.
• If the pilot flange diameter is less than 2.125 in. (53.975 mm) or is not in compliance with
dimensions shown in Figure 27
• If the crankshaft trigger gear assembly does not have the larger scallops as shown in Figure 26
• Damaged counterbore face of the crankshaft trigger gear assembly
• If the crankshaft trigger gear assembly has a hole, slot, or tang and there are any nicks or dents on
the hole, slot, or tang; nicks or deformities on the slot and teeth of the crankshaft trigger gear
assembly
• Pitting, galling, fretting, or wear
• Crankshaft gear that fails magnetic particle inspection
• Clearance between the mating surfaces of the installed crankshaft trigger gear assembly and
crankshaft counterbore (There must not be any clearance when the crankshaft trigger gear assembly
is installed.)
Crankshaft Counterbore Inspection
CAUTION LYCOMING ENGINES NO LONGER ALLOWS REWORK OF THE
COUNTERBORE.
COUNTERBORE THREADS IN THE FIELD. IF THIS TYPE OF REPAIR IS
NECESSARY, IT IS RECOMMENDED THE CRANKSHAFT BE SENT TO THE
FACTORY (THROUGH AN AUTHORIZED LYCOMING DISTRIBUTOR)
WITH PAPERWORK THAT IDENTIFIES THE NECESSARY REPAIR.
NOTICE: Prior to inspection, the crankshaft counterbore must be clean, dry, and free of debris.
Refer to the "Crankshaft Counterbore Cleaning" procedure in Chapter 05-30.
Make sure the threads in the
counterbored end of the crankshaft are
intact and not galled, stripped, or
damaged.
Measure the Inside Diameter (ID) of the
crankshaft counterbore at the rear of the
crankshaft to make sure there is a correct
fit between the ID of the crankshaft and
the Outside Diameter (OD) of the
crankshaft trigger gear assembly pilot
flange. The crankshaft counterbore
diameter at the rear of the crankshaft
must not be more than 2.126 in. (54.000
mm) when measured at any location.
© 2018 Avco Corporation. All Rights Reserved
November 2018
Comments
DO NOT TRY TO REPAIR
If the threads are galled, stripped
or damaged, it is recommended
the crankshaft be sent to
Lycoming Engines (through an
authorized Lycoming distributor)
with paperwork that identifies the
type of damage. Do not try to
repair the threads in the field.
If the diameter is oversized,
replace the crankshaft.
Lycoming Engines no longer
approves rework or repair of an
unacceptable crankshaft
counterbore diameter.
Findings/
Done
Corrective Action
THE CRANKSHAFT
72-20
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