Figure 3-31.—Gauge used for measuring bolt elongation.Figure 3-32.—Measuring bolt elongation.and figure 3-32 illustrates the gauge in use. The properelongation is listed in the engine manufacturer’stechnical manual.After you reassemble a bearing, always bar or jackover the engine by hand through several revolutions.Check to see that all reciprocating and rotating partsfunction freely and that the main and connecting rodbearings do not bind on the crankshaft. Turn larger dieselengines over first by the manual jacking gear providedand then by the engine starting system.Figure 3-33.—Measuring bearing shell thickness.Figure 3-34.—Checking bearing clearance with a Plastlgage.MEASURING BEARING CLEARANCESDo not use leads, shim stock, or other such items todetermine clearance of precision bearings. These itemsmay seriously damage the soft bearing material. Instead,use a micrometer fitted with a spherical seat to measurethe thickness of bearing shells. Place the spherical tipagainst the inside of the bearing shell to obtain anaccurate reading and to prevent injury to the bearingmaterial. Figure 3-33 shows a micrometer caliper fittedwith a steel ball for measuring bearing thickness.An alternate method for determining clearance iswith a Plastigage (fig. 3-34). The Plastigage will not3-21
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