Valve Guide: Testing and Inspection

TOOL REQUIRED
- J 26900-1 Outside Micrometer
- J 26900-14 Small Hole Gages

MEASURE





1. Valve stem diameter using a Outside Micrometer and record the measurement The standard diameter for intake valve stems is 6.965 to 6.980 mm (0.2742 to 0.2748 inch) and 6.950 to 6.965 mm (0.2737 to 0.2742 inch) for exhaust valve stems. Measure the diameter at more than one place along the length of the valve stem. Record measurement.





2. Valve guide inside diameter using a Small Hole Gages with the Outside Micrometer. Insert the appropriate size Small Hole Gages into the valve guide and measure the inside diameter. Remove the Small Hole Gages and, using the Outside Micrometer, read the diameter of the Small Hole Gages and record the measurement. The standard inside diameter of valve guides is 7.000 to 7.015 mm (0.2756 to 0.2761 inch) for both intake and exhaust valve guides. Measure the diameter at more than one place along the length of the valve guide. Record measurement.
3. Valve stem-to-valve guide clearance by subtracting the valve stem outside diameter measurement from the valve guide inside diameter measurement. Standard clearances are 0.020 to 0.050 mm (0.0008 to 0.0019 inch) for the intake valves and 0.035 to 0.065 mm (0.0014 to 0.0025 inch) for the exhaust valves. If the intake valve guide clearance exceeds 0.070 mm (0.0027 inch), replace the intake valve and valve guide. If the exhaust valve guide clearance exceeds0.090 mm (0.0035 inch), replace the exhaust valves and valve guides.