Service Bulletin No. 530 B

Application of Protective Coating on Crankshaft


Supersedes Service Bulletin No. 530A

November 22, 2004


The following Lycoming four cylinder engines which utilize fixed pitch propellers except new engines shipped after February 15, 1997.

All 235 series engines;

All 290 series engines;

All 320 series engines;

and All 180 horsepower, 360 series engines except O-360-A4A, -A4AD, -A4D, -A4G, -A4J, -A4K, -A4M, -A4N, -A4P, -A5AD, -C4F, -C4P, IO-360-L2A and AEIO-360-B4A engine models.


At overhaul or earlier at owner’s discretion.

A protective coating, Urethabond 104*, is available to apply to the crankshaft ID in the flange area to prevent corrosion pitting. This coating has been incorporated on new crankshafts shipped in engines and as spares since February 15, 1997. These crankshafts are identified by “PID” stamped on the OD of the crankshaft flange.

Supplement No. 1 to Service Bulletin No. 530B

For more information on Protection Coating on Crankshafts, refer to Supplement No. 1 to Service Bulletin No. 530B.