Check and Adjust Engine Valve Lash

CAUTION: To prevent accidental starting of engine while performing valve adjustment, ALWAYS disconnect NEGATIVE (-) battery terminal.

IMPORTANT: Engine valve clearance MUST BE checked and adjusted with engine COLD.

NOTE: If desired, have your authorized servicing dealer or engine distributor adjust the engine valve clearance.

2. Remove rocker arm cover.

IMPORTANT: Visually inspect contact surfaces of valve tips and rocker arm wear pads. Check all parts for excessive wear, breakage, or cracks. Replace parts that show visible damage.

Rocker arms that exhibit excessive valve clearance should be inspected more thoroughly to identify damaged parts.

3. Set engine to No. 1 or No. 4 "TDC-Compression" using the JDE-81-1 Engine Rotation Tool and the JDE-81-4 Timing Pin. Rotate flywheel until timing pin fits into hole in flywheel.

4. Determine what cylinder (1 or 4) is pinned by moving push rods of each cylinder (1 or 4). Only the cylinder that has both the intake and exhaust push rod loose is pinned by the JDE-81-4 Timing Pin. Both push rods loose indicates the piston is at top dead center (TDC) on compression stroke.

5. If No. 1 cylinder is pinned, set exhaust valve No. 1, and No. 3. Set intake valves (B) No. 1 and 2.

A-No. 1 TDC Compression Stroke
B-No. 1 TDC Exhaust Stroke
C-Fan End of Engine

CED,OUO1002,470 -19-23FEB98-1/2

Specification

If No. 4 cylinder is pinned, set exhaust valves (A) No. 2 and No. 4. Set intake valves (B) No. 3 and 4.

6. Remove timing pin, rotate flywheel one revolution (360°), and insert timing pin. Set valve clearance.

7. Clean cylinder head and rocker arm cover mating surfaces.

8. Install a new rocker arm cover gasket. DO NOT use any sealant on the gasket.

9. Install rocker arm cover. Tighten cap screws to 108 N·m (96 lb-in). Do not overtighten cap screws.

10. Remove flywheel turning tool and install timing pin.

CED,OUO1002,470 -19-23FEB98-2/2