GMC 1990 Light Truck Repair Manual page 457

Rocker arm stud.
• Place J 5802-01 over the rocker arm stud.
• Install a nut and flat washer.
• Turn the nut to remove the stud.
Install or Connect (Figure 22)
0
Tools Required:
J 5715, Reamer (0.003-inch oversize)
or
J 6036, Reamer (0.013-inch oversize)
J 6880, Rocker Arm Stud Installer
NOTICE: Do not attempt to install an oversize
rocker arm stud without reaming the stud hole
as this could damage the cylinder head.
• Ream the hole to the proper size for the
replacement oversize rocker arm stud. Use J 5715
for 0.003-inch oversize studs; J 6036 for 0.013-inch
oversize stud (figure 23).
• Coat lower end (press-fit area) of rocker arm stud
with hypoid axle lubricant.
• Rocker arm stud. Use J 6880 (figure 22). Stud is
installed to proper depth when the tool bottoms on
the cylinder head.
ASSEMBLY
Install or Connect (Figures 19, 20, and 24)
Tools Required:
J 8062, Valve Spring Compressor
J 23738-A, Vacuum Pump
4.3 LITER V-6 6A3-15
1. Valves (27 and 29).
• Lubricate the valve stems with engine oil.
• Insert the valves into the proper seats.
2. Seal (24) (intake valve only).
• Install the seal over the valve stem and seat it
against the head.
3. Springs and dampers.
4. Shields (22).
5. Cap (21) or rotator (28).
6. O-ring seals (23) and valve keepers (20).
Figure 24—Checking the Valve Seals
B-07869