HEAD 1916149 - Caterpillar

(1) Gear. If new gear is required, replace camshaft assembly. The heat treatment of the gear is damaged if heated.(2) Diameter of the surfaces (journals) for the camshaft bearings (new) ... 69.850 0.013 mm (2.7500 .0005 in) Bore in front bearing for the camshaft (after assembly) ... 69.969 0.048 mm (2.7547 .0019 in)Bore in the other six bearings for the camshaft (after assembly) ... 69.982 0.061 mm (2.7552 .0024 in)(3) Thickness of thrust plate (new) ... 4.65 0.03 mm (.183 .001 in) Thickness of groove in camshaft for thrust plate (new) ... 4.83 0.06 mm (.190 .002 in)End play of the camshaft ... 0.10 to 0.26 mm (.004 to .010 in)(4) Camshaft. (5) Height of camshaft lobes.To find lobe height, 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 actual lobe lift (6).D. Specified camshaft lobe lift (6) is: a. Exhaust lobe ... 10.210 mm (.4019 in)b. Inlet lobe ... 10.212 mm (.4021 in)Maximum permissible difference between actual lobe lift (STEP C) and specified lobe lift (STEP D) is 0.13 mm (.005 in).Inlet Valve Timing
1. Check the No. 1 inlet valve lash with the engine stopped. The valve lash must be 0.30 to 0.46 mm (.012 to .018 in). If the valve lash is not in this range, adjust the lash to 0.38 mm (.015 in).2. Mark Top Center Position of the crankshaft of the vibration damper or pulley.3. Use a dial indicator to measure the inlet valve movement.4. Rotate the crankshaft in the direction of normal engine rotation. Stop when the inlet valve is 1.91 mm (.075 in) off its seat in the opening sequence.At this point the crankshaft Top Center Position Mark must be ... 1 2 degrees After Top Center