46-06-03 KINNER: (Was Mandatory Note 5 of AD-707-2: 9 of AD-749-1: Special Note 12 of AM-231 and 4 of AD-336.) Applies Only to Fairchild 24J, 24JS, and 24W Series, Jobmaster DGA-18K, Meyers OTW-160, and Ryan ST-3KR Airplanes Having R-5 Series 2 (Military R-540-2) Engines, R-55 (R-540-1) Engines of the Following R-56 (R-540-3) Engines: 12005 to 12319 Inclusive; 12805 to 12846 Inclusive; 12938 to 12948 Inclusive; 12950 to 12952 Inclusive; 12954 to 12961 Inclusive; 12963 to 12973 Inclusive; 12975 to 12976 Inclusive; 13034 to 13037 Inclusive; and 13040 to 13056 Inclusive.
Rework required immediately, if total engine time has already exceeded 500 hours, or if not, rework must be accomplished before exceeding 500 hours.
Grind the master rod knuckle pinholes to a fit of 0.0003 to 0.0008-inch (tight) with the knuckle pins. This will necessitate reboring the connecting rod bushings, replacement of the knuckle pins and wrist pin bushings. The letter "O" preceding the engine serial number will indicate that this rework has already been accomplished.
(Kinner Service Bulletins Nos. KCE-33 and KCE-4 cover this same subject.)