Check and Adjust Engine Valve Clearance (6090 Engines)

CD31264-UN-16DEC10

Lock Engine at Top Dead Center

CD31265-UN-16DEC10

Valve Clearance Setting Procedure

A - Flywheel Turning Tool

B - Timing Pin

C - Rocker Arm Foot

D - Feeler Gauge Access

Adjust engine valve clearance as follows or have your authorized servicing dealer or engine distributor adjust the engine valve clearance.

1. Remove rocker arm cover and crankcase vent tube.

2. Using JDE83 or JDG820 Flywheel Turning Tool (A), rotate engine flywheel in running direction (clockwise viewed from water pump) until No. 1 piston (front) has reached top dead center (TDC) on compression stroke. Insert timing pin JDG1571 (B) into flywheel bore.

   NOTE: To assist in adjusting valve clearance, push the rocker arm foot (C) forward for easier feeler gauge access (D).

3. 
   RG13946-UN-04FEB05

   Checking Valve Clearance Using Bent Feeler Gauge

   
   CD31266-UN-16DEC10

   Valve Adjusting Sequence - No. 1 Cylinder at TDC

   A - Front of Engine

   With engine locked at ”TDC” of No. 1 piston's compression stroke, use a bent feeler gauge to check valve clearance on Nos. 1, 3, and 5 exhaust valves and Nos. 1, 2, and 4 intake valves. If out of specification, loosen lock nut on rocker arm adjusting screw. Turn adjusting screw until feeler gauge slips with a slight drag. Hold the adjusting screw from turning with screwdriver and tighten lock nut to specifications.

   Item	Measurement	Specification
   Intake Valve Clearance (Rocker Arm-to-Valve Tip With Engine Cold)	Clearance	0.18 mm (0.007 in.)
   Exhaust Valve Clearance (Rocker Arm-to-Valve Tip With Engine Cold)	Clearance	0.64 mm (0.025 in.)
   Valve Adjusting Screw Lock Nut	Torque	27 N•m (20 lb.-ft.)

   Recheck clearance again after tightening lock nut. Readjust clearance as necessary.

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4. 
   RG13839-UN-04APR08

   Valve Adjusting Sequence - No. 6 Cylinder at TDC

   A - Front of Engine

   Remove timing pin and rotate flywheel 360°, then reinstall timing pin. No. 6 piston is now at ”TDC” of its compression stroke. Rocker arms for No. 6 piston should be loose.

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5. Check and adjust valve clearance to the same specifications on Nos. 2, 4, and 6 exhaust and Nos. 3, 5, and 6 intake valves.