40 SENR9977 Testing and Adjusting Section Broken socket on the upper end of a pushrod b. Place the appropriate feeler gauge (2) between the rocker arm and the valve. Turn adjustment screw (1) while the valve adjustment screw locknut is being held from turning. Adjust the valve lash until the correct specification is achieved. Loose adjustment screw for the valve lash If the camshaft and the valve lifters show rapid wear, look for fuel in the lubrication oil or dirty lubrication oil as a possible cause. The valve lash is measured between the top of the valve stem and the rocker arm lever. c.
After each adjustment, tighten the valve adjustment screw locknut while adjustment screw (1) is being held from turning. Note: An adjustment is not necessary if the measurement of the valve lash is in the acceptable range. Inspect the valve lash while the engine is stopped. The temperature of the engine does not change the valve lash setting. 3. Rotate the crankshaft in a clockwise direction that is viewed from the front of the engine. When the inlet valve of the No. 2 cylinder has opened and the exhaust valve of the No. 2 cylinder has not completely closed measure the valve lash of the inlet valve and the exhaust valve of the No. 3 cylinder. Note:
When the following procedures are performed, the front housing must be installed. If adjustment is necessary, refer to Steps 2.a, 2.b, and 2.c above. 4. Rotate the crankshaft in a clockwise direction that is viewed from the front of the engine. When the inlet valve of the No. 1 cylinder has opened and the exhaust valve of the No. 1 cylinder has not completely closed measure the valve lash of the inlet valve and the exhaust valve of the No. 4 cylinder. If adjustment is necessary, refer to Steps 2.a, 2.b, and 2.c above. 5. Rotate the crankshaft in a clockwise direction that is viewed from the front of the engine. When the inlet valve of the No.
3 cylinder has opened and the exhaust valve of the No. 3 cylinder has not completely closed measure the valve lash of the inlet valve and the exhaust valve of the No. 2 cylinder. g01016764 Illustration 47 Setting the valve lash If adjustment is necessary, refer to Steps 2.a, 2.b, and 2.c above. (1) Adjustment screw (2) Feeler gauge 6. Install the valve mechanism cover. Refer to Disassembly and Assembly, “Valve Mechanism Cover - Remove and Install”. 1. Remove the valve mechanism cover. Refer to Disassembly and Assembly, “Valve Mechanism Cover - Remove and Install”. 2. Rotate the crankshaft in a clockwise direction that is viewed from the front of the engine. When the inlet valve of the No.
4 cylinder has opened and the exhaust valve of the No. 4 cylinder has not completely closed measure the valve lash of the inlet valve and the exhaust valve of the No. 1 cylinder. If necessary, make adjustment. a. Loosen the valve adjustment screw locknut that is on adjustment screw (1).