ENGINE 98 Fig. 6 Fig. 7 CRANKSHAFT REMOVAL (Cylinder head, flywheel, oil sump, oil pump, pistons with connecting rods, and crankshaft pulley removed). 1 Unscrew timing gear housing cover and remove by tapping it evently over two dowel pins. 2 Unscrew and remove timing housing lower half. 3 Check/mark set number of main bearing caps with respect to crankcase. Unscrew bolts of main bearing caps. Tap main bearing caps with plastic mallet and remove caps with bearing shells. 4 Lift crankshaft carefully from crankcase. 5 Remove bearing shells and 2nd journal thrust washers from crankcase and main bearing caps. Mark them suitably in case they are required to be reused. 6 Remove sealing rings at 5th main bearing from crankcase and main bearing cap. 7 Inspect crankshaft gear for wear, scoring, etc. If necessary, pull it out using puller, 312 589 07 33 Fig. 6 and remove woodruff key. INSPECTION AND REPAIR OF CRANKSHAFT 1 Clean and carry out visual inspection of crankshaft for following: a. Overheating of journals – This is indicated by bluish/brown colour on journals/pins. b. Scoring marks on journals/pins. c. Cracks – It is preferable to check this on magnetic crack detection. 2 Check hardness of journals and crankpins by using skelerograph. 3 Support crankshaft on V-blocks on a surface plate at 1st and 5th main journals. Check runout of remaining journals. Fig. 7. 4 If runout exceeds permissible limits, carefully straighten crankshaft in cold condition on a press, till runout is within permissible limits. 5 Check lateral and radial runouts of flywheel mounting flange. 6 Measure main journal and crankpin diameters. 7 If necessary, re-grind main journals and crankpins to next repair size after removing counterweights (where required). Maintain correct fillet radii for man journals and crankpins. NOTE: Care must be taken during grinding to ensure that width of main journals is not unnecessarily increased. Should it be necessary to grind sides of 2nd main bearing journal, grind it to next repair size.
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