3306 TRUCK ENGINE Caterpillar

(15)Governor

1. Remove tachometer drive cable (or cap) from the tachometer drive housing, and install an accurate tachometer.

This adjustment should be made by an authorized dealer.

2. See the Engine Specifications Chart for high and low idle settings.

(16)Air Fuel Ratio Control

Slow engine response and low power may indicate a need for repair or adjustment by your Caterpillar dealer.

(17)Engine Valve Lash

If valve clearance is within ± .003 inch (0.07 mm) of the clearance given, adjustment is not required. If clearance is not within these limits, adjust the valves. Adjust valves with the engine stopped and cold.

To Inspect Valve Lash

1. Remove the plug located on the flywheel housing.

A flywheel turning tool is available from your Caterpillar dealer. Consult your Caterpillar dealer for proper instructions for use of the tool.

2. Disconnect and remove starting motor and install turning tool, if used.

3. Turn the flywheel to close No. 1 exhaust and inlet valves, aligning plug hole in the flywheel housing with the hole in the flywheel.

4. Install a 2-1/2 inch (6.35 mm) long 3/8 inch NC bolt into the flywheel, through the flywheel housing. This determines Top Dead Center (TDC) of No. 1 cylinder.

5. Measure lash for No. 1, 3 and 5 exhaust valves, and No. 1, 2 and 4 inlet valves.

6. The correct size feeler gauge should pass between the rocker arm and the valve stem with a slight drag.

7. Adjust valves if necessary.

8. Remove bolt from flywheel.

9. Turn flywheel 360° to close No. 6 inlet and exhaust valves. Install bolt in flywheel.

10. Measure lash for No. 2, 4 and 6 exhaust, and No. 3, 5 and 6 inlet valves. Adjust if necessary.

11. Remove bolt from flywheel and install plug in flywheel housing.

12. Remove the engine turning group and install the starting motor.

To Adjust Valves

1. Loosen the locknut on the adjusting screw.

2. Turn the adjusting screw to obtain the proper lash.

3. Hold the adjusting screw and tighten the locknut to 22 ± 3 lb.ft. (28 ± 4 N·m).

4. Measure the valve lash.

Observe Valve Rotation

After adjusting valve lash, and before installing the valve cover:

1. Start the engine and run at low idle.

2. Watch the valve rotocoils for rotation.

3. Each valve rotocoil should turn slightly each time the valve opens. If a valve fails to rotate, contact your Caterpillar dealer for service.

4. Stop the engine. Inspect the valve cover gasket. Use a new gasket if the used gasket is damaged.

5. Install the valve cover. Tighten bolts to 8 ± 2 lb. ft. (11 ± 3 N·m).