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VALVE GUIDES The valve guides are an integral part of the engine cylinder head and are not replaceable. When the valve stem guide clearance is excessive, the valve guide bores must be reamed oversize. Ser- Corresponding oversize valve stem seals are also available and must be used with valves having 0.381 NOTE: If the valve guides are reamed oversize, the VALVE STEM-TO-GUIDE CLEARANCE Valve stem-to-guide clearance may be measured by either of the following two methods. PREFERRED METHOD: (1) Remove the valve from the head. and a bristle brush. (3) Insert a telescoping gauge into the valve stem guide bore approximately 9.525 mm (.375 inch) from (4) Remove and measure telescoping gauge with a micrometer. (5) Repeat the measurement with contacts length- wise to engine cylinder head. (6) Compare the crosswise to lengthwise measure- ments to determine out-of-roundness. If the measure- (7) Compare the measured valve guide bore diam- eter with specifications (7.95-7.97 mm or 0.313-0.314 Fig. 13 Valve Facing Margin 1 – 0.787 MM (1/32 INCH) VALVE MARGIN Fig. 14 Measurement of Valve Seat Runout 1 – DIAL INDICATOR Fig. 15 Measurement of Valve Guide Bore Diameter 1 – GAUGE 9 - 16 2.5L ENGINE XJ SERVICE PROCEDURES (Continued) |