Service Bulletin No. 625

Alternator Fan Backplate


DATE: February 2, 2016


Lycoming engine models IO-360-A1B6, IO-360-C1G6, TIO-360-C1A6D, IO- 540-K1G5, TIO-540-AH1A, and AEIO-580-B1A that have alternator assembly part number (P/N) 32C21703 or 32C22492 and any spare alternator assemblies P/N 32C21703 or 32C22492.


At the next regularly scheduled maintenance event but not later than 12 months after the effective date of this Service Bulletin (whichever occurs first.)

This Service Bulletin is notification of a requirement to replace specific alternator assemblies identified herein as a corrective action for potentially non-conforming alternator fan backplates in the field. Continued operation of an alternator with a non-conforming alternator fan backplate can cause undue flex and stress on the backplate during engine operation.

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