BOLT-SOCKET HEAD 1668636 - Caterpillar

(18)Engine Valve Lash
To prevent possible injury, when rotating flywheel, do not use starter motor to turn flywheel. Engine may start.
With the engine stopped and cold, inspect and adjust the bridge and valve adjustment. Always turn the flywheel in direction of normal rotation.
Valves must be closed for bridge and valve lash adjustment.There are two rocker arms (A), per cylinder. One rocker arm for the two exhaust valves and one rocker arm for the two inlet valves. Each pair of valves is connected by a bridge (B), which is actuated by the rocker arm. The valves in each pair are adjusted simultaneously by the adjusting screw (C), in the rocker arm. Each bridge is adjusted by adjusting screw (D). 1. Clean the area around the valve covers. Remove the covers. 2. Remove the timing bolts (1), and plug (2). Remove cover.3. Install engine turning tool, 5P7307 available from your Caterpillar dealer.4. Turn the pinion to align the hole in the flywheel with the hole in the flywheel housing.5. Install the timing bolt in the flywheel. This is the top bolt of the two bolts that secure the flywheel housing cover.Bridge Adjustment
Adjustment of the bridge will be necessary only after grinding the valves or other work on the cylinder head is done.Valves must be fully closedIf bridge was removed perform steps 1 and 2 that follow. If bridge was not removed, proceed to step 3.1. Put engine oil on the bridge dowel in the cylinder head and in the bore in the bridge.2. Install the bridge with the adjustment screw toward the exhaust manifold. 3. Back off adjusting the screw several turns (counter-clockwise). Make sure it is not in contact with the valve stem.4. Firmly press straight down on the rocker arm, above point of contact with bridge.5. Turn the adjusting screw clockwise until contact is made with the valve stem. Turn the adjusting screw an additional 30° (one-twelfth turn). 6. Hold the adjusting screw in this position. Tighten the locknut to 22 3 lb. ft. (30 4 N m).7. Put engine oil at the point where the rocker arm makes contact with the bridge.After checking the bridge adjustment, make the valve lash adjustment.Engine Valve Lash Adjustment
To prevent possible injury, do not use the starter motor to turn the flywheel.Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve clearance.
Measure the valve lash with the engine stopped. To obtain an accurate measurement, allow at least 20 minutes for the valves to cool to engine cylinder head and block temperature.
If the valve clearance is within 0.08 mm (.003 in) of the nominal clearance given, adjustment is not required. If the clearance is not within these limits, set the clearance as given in the chart. 1. Put No. 1 piston at top dead center (TDC) on the compression stroke.2. With No. 1 piston at top dead center (TDC) on compression, and timing bolt installed, measure lash between the bridge and rocker arm on