AD 50-32-01

50-32-01 CONTINENTAL: Applies to All Airplanes Equipped With Continental Model E185-3 Engines Serially Numbered 4514-D and Below, E185-1 Engines Serially Numbered 4566-D and Below and E165-2 Engines Serially Numbered 10025 and Below. This Includes Navion, Beech Model 35 and Temco (Luscombe) Model 11A Airplanes. Compliance required each 10 hours of operation as indicated. AD 49-02-04 describes an inspection procedure to preclude the possibility of sudden oil pump failure (and almost immediate complete engine failure resulting therefrom) due to shearing of the square corners of the oil pump drive gear shaft. There have been a few recent oil pump failures which could have been avoided by continuation of periodic wear checks of the oil pump drive until the related parts are proven satisfactory by teardown inspection and/or replacement. Therefore, the following should be accomplished on all engines in the serial number ranges indicated above which have not already complied withContinental Service Bulletin No. M48-15: Remove tachometer drive cable and insert tapered flat end of Continental Drive Fit Indicator flat end of Continental Drive Fit Indicator (P/N 530757) in slot of tachometer drive shaft, tapping slightly to be sure it is tight in place. By holding the graduated indicator with one finger, and moving the bar with another, a reading (in degrees) of total backlash is obtained. Total backlash should not exceed 15 degrees. If total backlash does not exceed 15 degrees, the wear check should be repeated at 10-hour intervals until the engine is overhauled and oil pump parts are dimensionally inspected and/or replaced, to determine whether or not excessive wear is accumulating. An accumulation of an additional 5 degrees indicated wear in 20 hours, over the original reading, whether a total of 15 degrees is reached or not, is sufficient to warrant replacement of parts as hereafter noted. A reading of more than 15 degrees on the indicator indicates excessive wear, a potential failure, and requires immediate replacement of worn parts prior to further operation of the airplane. Parts affected include the oil pump drive gear, oil pump housing, accessory case, and cam gear. The cam gear need not be replaced if concentricity check shows total runout of square holes to be less than 0.004 inch. At the time of major overhaul (or first disassembly), oil pump drive parts as per Continental Service Bulletin No. M48-15, should be checked and replaced if necessary. These parts are the oil pump drive gear and cam gear. The wear check can be made at any Continental Authorized Service Station, and involves only a few minutes for accomplishment. (Continental Service Bulletins Nos. M48-14, with supplements Nos. 1 and 2, and M48-15, cover this same subject.) This supersedes AD 49-02-04.