TM-9-2815-220-34 Direct Support Manual for AVDS-1790-2C and AVDS-1790-2D Engines Download
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) ) Fig10-e 326. l 11stalli11g v(l/vc rucke, . al'm cot•c» and adjusting i11take valve c/eara11ce rculi11der No. 6R). TA0/1A1 " r Figure 3-327. Adjusting exhaust 11al+e-clearn11ce . justing screw pad to make sure seat is flat on valve stem and torque tighten adjusting screw lock nut to 175 pound-inches. i. Slowly tu camshaft (fig. 3-328) clockwise, as viewed from flywheel end, until No. 6R intake valve has just closed. Closing point is determined by trying to rotate the swivel pad on the intake valve adj lsting screw while the camshaft is being TM 9-2815-220-34 Figure .fl. Determi11i11g closing point of No. 6 i11take valve. rotated. The valve is closed the instant the swivel pad is free to move. NOTE Do not force camshaft drive. The shaft is machined with a 24-tooth spline on inner end, and a 28-tooth spline on outer end. This difference in number of teeth pro- vides a vernier effect which makes it pos- sible to index the drive shaft so it will engage the splines of the camshaft drive gearshaft and camshaft drive bevel gear- shaft at some point within 360 degrees. An accurate setting is then provided without changing the relationship of the camshaft and crankshaft. j. Maintain the position of camshaft as set in figure 3-328 and the crankshaft position set in fig. ure 3-325. Insert camshaft drive shaft (tig. 3-329) using mechanical puller part number 8761297, and mate splines on drive shaft with splines in cam- shaft drive bevel gearshaft. When splines of d1;ve shaft do not mate with splines of camshaft gear- shaft, withdraw drive shaft and turn slightly be- fore again attempting insertion. NOTE It may be necessary to repeat this opera- tion a number of times before splines will mate and allow ddve shaft to be inserted into position. k. Check valve timing by rotating crankshaft clockwise as viewed from rear, approximately 1/8 turn to remove gear backlash, then turn coun- terclockwise until the valve is just closed. Stop rotating the crankshaft the instant the swivel pad becomes free. Observe position of flywheel timing mark. When timing mark on flywheel is alined within 1/8 inch of the timing pointer, the valve Change 1 3·233