TELEDYNE CONTINENTAL AIRCRAFT ENGINE CATEGORY 4 …

1 ISSUEDREVISEDPAGE NO REVISIONMODAYYEARMODAYYEAR1 of 3052897 SID97-8 1997 TELEDYNE INDUSTRIES MOTORSAn Allegheny TELEDYNE Box 90 Mobile Alabama 36601 Ph. 334-438-3411 TELEDYNE CONTINENTAL AIRCRAFT ENGINESERVICE INFORMATION DIRECTIVEC ompliance Will Enhance Safety, Maintenance or Economy ofOperationSUBJECT: INTERFERENCE OF TCM 24 VOLT 60 AMPERE GEAR DRIVEN ALTERNATOR AND CRANKCASE THROUGH BOLTPURPOSE:To require inspection for interference between alternator drive end housing andthrough bolt, to detail alternator housing rework, and to ensure clearance between thealternator housing and adjacent through bolt at the time of alternator :At each alternator installation or ENGINE :All New and Rebuilt TELEDYNE Crittenden and TELEDYNE CONTINENTAL Motors 24 Volt,60 Ampere Gear Driven Alternators, P/N's: 642055, 646490, 646843, 646845, and allspare drive end housings 642957 and to ENGINE Models.

2 IO-520-BTSIO-520-JGTSIO-520-HIO-520-BATS IO-520-JBGTSIO-520-KIO-520-BBTSIO-520-KG TSIO-520-LIO-520-CTSIO-520-KBGTSIO-520-M IO-520-CBTSIO-520-LGTSIO-520-NIO-520-MTS IO-520-LBIO-550-BIO-520-MBTSIO-520-NIO-5 50-CTSIO-520-BTSIO-520-NBIO-550-GTSIO-52 0-BBTSIO-520-UBIO-550-NTSIO-520-DTSIO-52 0-VBTSIO-550-BTSIO-520-DBTSIO-520-WBTSIO -550-CTSIO-520-EGTSIO-520-CTSIO-550-ETSI O-520-EBGTSIO-520-DGENERAL INFORMATION:Occasionally interference is experienced betweenone of the ENGINE through bolts and the drive endhousing of affected alternators. This bulletinprovides instructions to rework the alternator driveend housing to insure clearance between thealternator housing and the crankcase through : New and Rebuilt P/N 646843 and646845 alternators subsequent to serial (June 17, 1996) and all spare driveend housings P/N s 642957 and 646496, shippedfrom TCM after June 16, 1996 have beenmodified in accordance with this ServiceInformation Directive.

3 Refer to Service BulletinM92-12, Figure 1, to interpret alternatormanufacturing Serial 4 SID97-8 FAA APPROVEDISSUEDREVISEDPAGE NO REVISIONMODAYYEARMODAYYEAR2 of 3052897 SID97-8 TELEDYNECONTINENTAL MOTORSAn Allegheny TELEDYNE Box 90 Mobile Alabama 36601 Ph. 334-438-3411 DETAILED INSTRUCTIONS:1. Pre-installation - Viewing the alternator mountpad on the Right Crankcase Half, insure theend of through bolt at lower left corner ofalternator mounting pad extends no furtherthan .850 inch from surface of crankcase. Ifbolt height in excess of .850 inch is noted:a. Gain access to both sides of throughbolt, loosen, and remove cadmiumplated washer and nuts. b. Reposition through bolt as required toobtain .850 inch maximum heightfrom the surface of the Lubricated threads with clean 50weight aviation ENGINE oil, installcadmium plated washer, nuts, andtorque both through bolt nuts to thespecified Install alternator on ENGINE in accordance withthe current applicable ENGINE overhaul for clearance between through bolt andalternator housing.

4 If interference occurs,remove alternator and perform modification asfollows:a. Using an appropriate grinding tool or - .812 diameter end mill cutter,contour housing as specified in Figure1. Insure a minimum radius at allcorners of .005 and wipe away chipsor dust. Treat with AccelagoldAluminum Conversion Coating, andapply enamel Reinstall alternator in accordance withthe current applicable ENGINE overhaulmanual. Verify through bolt does notcontact At time of alternator overhaul or replacement,insure alternator housing is contoured asspecified in Figure Make logbook entries indicating compliancewith this Service CONSIDERATIONAll affected equipment will be covered by theTCM Gold Medallion warranty as applicable,subject to its terms and conditions. Warrantyclaims may be filed through any TCM to.

5 5 hours labor will be allowed per :We recommend that you make the appropriate annotations to applicablemanuals to call attention to this service NO REVISIONMODAYYEARMODAYYEAR3 of 3052897 SID97-8 1997 TELEDYNE INDUSTRIES MOTORSAn Allegheny TELEDYNE Box 90 Mobile Alabama 36601 Ph. - .41 R(ref)(.750 - .812 dia. grind stone or cutter).24 - .26(center line of grind stone or cutter).38 - .41 R(ref).85 - . - (center line of grind stone or cutter)Figure 1