SAFARI

ENGINE 104 Fig. 20 Fig. 21 INSPECTION AND REPAIR OF CAMSHAFT AND CAMSHAFT BUSHINGS 1 Carry out a visual inspection of camshaft for: i. Cracks, preferably check on a magnetic crack detector. ii. Overheating of journals, to be judged by colour of journal bluish/brown colour indicates overheating. iii. Deep scoringmarks on journals and cams. iv. Check hardness of journals and cam lobes with skelerograph. It should be within specified limits. v. Oil pump drive gear teeth for wear. vi. Check condition of oil passage plug on rear face of No. 3 camshaft journal. Replace plug, if necessary. 2 Inspect dimensionally camshaft journals and their runout. 3 If found beyond permissible limits grind camshaft journals to next repair size. 4 Inspect dimensionally camshaft bushes in crankcase. 5 If found worn beyond specified limits, remove them from crankcase with drift, 312 589 07 39 and sleeve, 312 589 07 39 and sleeve, 312 589 33 39 Fig. 20. Pry out expansion plug at 3rd bearing before removal of this bush. 6 Fit new bushings with same tool. 7 Line bore camshaft bushings in accordance with dimensions of camshaft bearing journals. 8 Fit expansion plug with special tool, Part No. 2523 5890 99 02 (Fig. 21) after coating its periphery with sealing compound. NOTE a. Camshaft bushes are serviced in semifinished condition. After installation in crankcase it is absolutely necessary to line bore them to camshaft journals sizes. b. Do not grind camshaft journals beyond last repair size. c. When fitting new camshaft bushings, following care should be taken i. Bushing having axial slot in bore should be fitted in parent bore for No. 1 journal, with slot to the front (oil flowing from this groove lubricates camshaft thrust washer and timing gears). Also ensure that two oil holes in this bushing are in line with drilled oil holes in crankcase. ii. No. 2, and 3 bearings are identical and are fitted with one hole in line with that in crankcase. iii. For manufacturing reasons, all camshaft bushings are provided with 2 holes. However, only No. 1 bearing utilizes both holes functionally whereas in others one hole is dummy.