Supplement No. 1 to Service Bulletin No. 553

Crankshaft Inspection for Lycoming Six Cylinder Turbocharged Engines


DATE: December 16, 2002

Supplement No. 1 to Lycoming Service Bulletin No. 553 provides the following additions or revisions:

1. Specific numbering information will assist in the identification of affected crankshafts. Lycoming crankshaft serial numbers are in one of the following formats:

a. “V5379” followed by 4 or 5 digits (1997 to present.)

b. An “I” followed by 5 digits (1996 – 1997.)

c. A “V” followed by a number of from 3 to 5 digits (1985 – 1996.)

d. A number of from 3 to 5 digits (pre 1985.)

2. Additions to Service Bulletin No. 553 effectivity.

a. To the list of affected engines in Service Bulletin No. 553, Table 1, add:


Engine Serial Number
TIO-540-AE2A L-9812-61A
TIO-540-AJ1A L-10116-61A
TIO-540-AJ1A L-10062-61A
TIO-540-AJ1A L-10417-61A
TIO-540-AH1A L-10274-61A
TIO-540-J2BD L-5644-61A


b. To the list of affected crankshafts in Service Bulletin No. 553, Table 2, add:

  • V53792797
  • V53793317
  • V53793778
  • V537910019
  • V537912939
  • V53795273

3. In order to ensure a more thorough inspection, six core samples will be removed rather than the three originally specified in Service Bulletin No. 553.

4. From the attached list of authorized core sample testing facilities (see Attachment I) customers must contact the facility of their choice to schedule core testing.

Service Bulletin No. 553

For more information on Crankshaft Inspection, refer to Service Bulletin No. 553.