49 ENGINE2.2LDICOR l Install piston rings in their respective position on piston using ring expander (Fig. 107). l Stagger piston rings gaps such that they are 120° apart (with butt gap not in line with piston pin) Fig. 107 CRANKSHAFT Clean and carry out visual inspection of crank shaft for Following l Overheating of journals, which is indicated by bluish brown colour l Scoring marks on journals l Cracks, which should be checked on magnetic crack detector l Check crank shaft run out by supporting it on Vblock at 1st and 5th main bearing journals (Fig. 108) l If run out exceeds permissible limits, straighten crank shaft in cold condition on press carefully. l Similarly check lateral and radial run outs of flywheel mounting flange. l Check crank shaft main bearing and crank pin journal dimension. l Record the readings in the format given at the end of this group. (Engine Inspection Sheets). If necessary, grind crank shaft main bearing and crank pin journals to next under-size. MAINTAINCORRECTFILLETRADIUSFORJOURNALS l Care must be taken during grinding to ensure that width of journals is not increased. l Should it be necessary to grind sides of 4th main bearing journal, grind it to next under size. l Re-chamfer oil holes on journals to avoid scoring of new bearing shells. Fig. 108
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