Service Bulletin No. 579 

DATE: November 16, 2007 

SUBJECT

Clearance Between Oil Sump Assembly and Oil Sump Baffle.

MODELS AFFECTED

New, rebuilt, overhauled,  or repaired  Lycoming  IO­540­L1C5;  TIO­540­ S1AD; IO­580­B1A series engines.

TIME OF COMPLIANCE

Whenever rivets or screws are found in the oil suction screen.

Lycoming has determined that on the above affected engines there may not be enough clearance between  the oil sump assembly P/N 77517 or P/N LW­14492 and the oil sump baffle P/N 56G23399 or P/N LW­ 13383. The  oil sump  baffle  may rub against the  oil sump  assembly causing  a  wear groove  on the  inner  surface of the oil sump assembly. Deformation of the oil sump baffle may further result in loosening of the  rivets used to attach the oil sump  baffle  vertical deflectors and of the screws used to attach the oil sump  baffle to the  oil sump supports. If either  the  rivets or screws become  unattached  it may lead  to  metal  contamination in the engine.