Service manual

6. Inspect the valve contact surface for the following:
• Undersized margin (1)
• Pitted surface (2)
• Burnt or eroded areas (3)
• Acceptable edge (margin) (4)
Valves with excessive damage must be
replaced.
Minor imperfections of the valve or valve seat
may be repaired.
7. Reconditioning of the valves and valve seats:
• The valves must seat perfectly for the engine
to deliver optimum power and performance.
• Cooling the valve heads is another important
factor. Good contact between each valve
and valve seat in the cylinder head is
necessary to insure that the heat in the valve
head is properly carried away.
• Regardless of what type of equipment is used,
it is essential that the valve guide bores are
free from carbon or dirt in order to ensure the
proper centering of the pilot in the valve guide.
The valve seats should be concentric to
within 0.05 mm (0.002 in) total indicator
reading.
• Reface pitted valves on a valve refacing
machine in order to ensure the correct
relationship between the valve head and the
valve stem.
Replace the valve if the valve stem is
excessively worn or warped.
Replace the valve if the edge of the valve
head is less than 0.79 mm (0.031 in) thick after
grinding.
• Several different types of equipment are
available for reconditioning valves and valve
seats. Follow the equipment manufacturer’s
recommendations for equipment use to attain
the proper results.
Valve Rocker Arm Stud Removal
SIE-ID = 195352
Tools Required
J 5802-01 Rocker Arm Stud Remover
Important:
• Valve rocker arm ball studs that have damaged
threads, or are loose in cylinder heads, should
be replaced.
• Valve rocker arm ball studs are pressed into the
cylinder head.
• New valve rocker arm ball studs are available in
0.0762 mm (0.003 in) and 0.3302 mm (0.013 in)
oversize.
1. Place the
J 5802-01 over the valve rocker arm
ball stud to be removed.
2. Install a nut and a flat washer.
156173
66507
Engine Engine Mechanical - 5.0L and 5.7L 6-81
2002 - Unit Repair (May 25, 2001)