TM 10-4320-226-146.6.4 EngineMaintenance.(continued)The main bearings are of the thin-shell type.Their properinstallation requires that webs in crankcase be inalignment and for bearing bores to be preloaded. Noattempt should be made to adjust or recondition bearingshells.h.Check bearing bores as follows:(1) position bearing caps, making sure that their identification numbersmatch with those stamped in crankcase.Torque down bolts in accordancewith appendix G.(2) Using inside micrometer, measure each main bearing base at points 1 and 2in plan "a", then in the same manner in plane "b" offset by 90 degrees(see figure 6-14), in order to determine any contraction, out-of-roundness or conicity.See table 6-1 for wear limits.(3) Install new bearings.(4) Position bearing cap, then preload and torque according to instructionsgiven in Table 6-1.(5) Using inside micrometer, measure each bearing bore and comparemeasurements to table 6-1.6.6.4.3 Assembly.a.b.c.d.Install deflector plate (figure 6-11, 11), notched nail (10) and sleevebearing (9).Install plug (8), washer (7), nozzle (6), plug (5), washer (4), and plug (3).Install two washers (2) and plugs (1).Install crankshaft (figure 6-10, 9) as follows:(1)(2)(3)(4)(5)(6)(7)Check locating pin in crankcase gearwheel.It should project 0.67 inch(17mm) from side opposite bearing identification mark. If necessaryinstall new locating pin.Install crankcase gearwheel with face bearing identification markdirected away from crankshaft (9).Install bearing halves (10) and bearing caps (6 and 7), making sure thatidentification marks are correct.Coat ring stops (11 and 12) with grease and stick them by their smoothfaces to first bearing web and first bearing cap.Install eight dowel bushings (8).Using oil, lubricate crankshaft journels and install crankshaft (9) withcrankshaft gear match mark positioned.Ensure bearing shells are seated in main bearing caps and bearing webs.6-30
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