TUBE 3454407 - Caterpillar

For installation of camshaft, the timing mark on the camshaft gear tooth must be in alignment with the timing mark on the tooth space of the crankshaft gear.(1) Diameter of the surfaces (journals) for the camshaft bearings (new) ... 63.500 0.013 mm (2.5000 .0005 in) Bore in the five bearings for the camshaft (new) ... 63.589 0.038 mm (2.5035 .0015 in)Maximum permissible clearance between bearing and bearing surface (journal) (worn) ... 0.18 mm (.007 in)(2) Tight fit between the gear and camshaft ... 0.030 to 0.071 mm (.0012 to .0028 in) Maximum permissible temperature of the gear for installation on the camshaft (do not use a torch) ... 316°C (600°F)(3) Endplay for the camshaft ... 0.18 0.08 mm (.007 .003 in) Maximum permissible endplay (worn) ... 0.51 mm (.020 in)(4) Width of thrust groove in camshaft (new) ... 9.14 0.05 mm (.360 .002 in) Diameter of thrust pin (new) ... 8.97 0.03 mm (.353 .001 in)Torque for thrust pin ... 48 7 N m (35 5 lb ft) (5) Height of camshaft lobes.To find lobe lift, use the procedure that follows:A. Measure camshaft lobe height (5).B. Measure base circle (7).C. Subtract base circle (Step B) from lobe height (Step A). The difference is the camshaft lobe lift (6).D. Specified camshaft lobe lift (6) is: 125-0454 Camshaft used with roller lifters:a. Exhaust lobe ... 9.40 mm (.370 in)b. Inlet lobe ... 9.30 mm (.366 in) 2W4238 Camshaft used with flat face lifters:a. Exhaust lobe ... 9.40 mm (.370 in)b. Inlet lobe ... 9.06 mm (.357 in)Maximum permissible difference between actual lobe lift (Step C) and specified lobe lift (Step D) is 0.25 mm (.010 in).