Pushrods, Rocker Arms, Balls, And Nuts; Hydraulic Lifters; Cylinder Head Disassembly; Cleaning And Inspection Of Cylinder Head Components - GMC T Series 1994 Repair Manual

PUSHRODS, ROCKER ARMS, BALLS, AND NUTS

>3*1 Clean
• All parts in clean solvent and dry them with com­
pressed air.
• Make sure the oil passages through the pushrods
are clear.
Inspect
Rocker arms and balls at their mating surfaces.
These surfaces should be free from wear or any
damage.
Rocker arm areas that contact the valve stems and
the socket areas that contact the ends of the push­
rods. These areas should be free of damage or
wear.
Rocker arm nuts.
Pushrod ends for scoring, roughness, or bends.
• Roll the pushrod on a flat surface to determine
its straightness. If the rod is bent, the rod will
not roll freely. Replace if necessary.

HYDRAULIC LIFTERS

This engine uses hydraulic roller type lifters.
Hydraulic lifters are serviced only as an assembly. No
internal parts are available. Service is limited to a disas­
sembly and cleaning. It is understood that most techni­
cians discard any suspicious valve lifters.
Important
Whenever the camshaft needs to be replaced, a
new set of hydraulic lifters must also be installed.

CYLINDER HEAD DISASSEMBLY

Remove or Disconnect (Figures 30 and 31)
Tool Required:
J 8062 Valve Spring Compressor
1. Valve keepers (67).
A. Compress the springs with J 8062 (figure 31).
B. Remove the keepers.
C. Remove J 8062.
2. Intake valve components.
A. Cap (68).
B. Shield (69).
C. Seal (71).
D. Damper (72).
E. Spring (73).
3. Exhaust valve components.
A. Rotator (75).
B. Shield (69).
C. Damper (72).
D. Spring (73).
4. O-ring seals (70).
5. Valves (74 and 76).
• Place the valves (74 and 76) in an organizer
rack so they can be replaced in their original
position at reassembly.
67. Valve Keeper
73.
68. Cap 74.
69. Shield 75.
70. O-Ring Seal
76.
71. Seal
72. Damper
67 75 69
Figure 30—Valves and Components
CLEANING AND INSPECTION
OF CYLINDER HEAD COMPONENTS
Refer to SECTION 6A and perform the following:
|in j|
Clean
Components as outlined.
Inspect
I?
Components as outlined.
Measure
• Valve stem clearance.
• Valve spring tension and free length.
Other information outlined includes:
• Valve and seat grinding.
• Valve guide reaming.
V0522