ARMY TM 9-6115-670-14&P 5-131 5.37.  VALVE CLEARANCE. This task covers:     Adjust INITIAL SETUP Tools General Mechanic's Tool Kit (Item 1, Appendix B) Equipment Conditions Engine shut down and allowed to cool completely. Generator assembly removed (para 5.24.). Materials/Parts None Flywheel adapter removed (para 5.33., REPLACE, step o). Valve cover removed (para 4.64.). ADJUST a.  Bring piston no. 1 to compression top dead center. Proceed as follows: (1)     Turn flywheel (1, Figure 5-29) until "1TC" (3) mark on flywheel (1) aligns with timing hole (2) in bell housing. (2)     Rotate flywheel cw and ccw about 15 and observe intake and exhaust valves on piston no. 1. If intake and exhaust valves on piston no. 1 do not move while rotating flywheel, piston no. 1 is in compression position. Proceed to step b. If intake and exhaust valves move while rotating flywheel, piston is in overlap position. Proceed to step a(3). (3)     Rotate flywheel 360. Realign "1TC" mark on flywheel with timing hole on bell housing and repeat step a(2). Piston no. 1 should be in compression position. b.  Refer to Figure 5-29 and use a feeler gauge to measure valve clearance (4) of intake and exhaust valves on piston no. 1, exhaust valve on piston no. 2, and intake valve on piston no. 3. Valve clearance (4) should measure between 0.0059 and 0.0073 in. (0.145 and 0.185 mm). c.  If valve clearance (4) is out of tolerance, loosen lock on adjusting screw, and turn adjusting screw to adjust clearance. CAUTION Use    retaining    nut    on    crankshaft    pulley    to    turn crankshaft.  Do not turn crankshaft by any other means. NOTES Looking  directly  at the flywheel, the timing  hole is located   above   speed   sensor   mounting   hole,   at approximately two o’ clock on the bell housing. When the “1TC” mark on the flywheel aligns dead center with the timing hole on the bell housing, piston no. 1 is either in the compression top dead center or overlap top dead center position.