Valve Train Components - Chevrolet 1991 Light Duty Truck Repair Manual

Figure 37—Installing the Oil Pump Pickup Tube and Screen (5.0L and 5.7L Engines)
| f f | Inspect
— Pump body (180) and cover (182) for cracks or
other damage.
— Gears (181 and 188) for wear.
— Drive gear and shaft (181) for lack of fit in the
pump body (180).
— Inside of the cover (182) for wear that would permit
oil to leak past the ends of the gears. The pump
gears, cover, and body are not serviced separately.
If the parts are damaged or worn, replace the
entire oil pump assembly.
— Pressure relief valve (183) for fit. The regulator
valve should slide freely in its bore without sticking
or binding. (Figures 35, and 36)
|njfc-| Assemble (Figures 35, 36 and 37)
Tool Required:
J 21882 Pickup Tube and Screen Installer
(5.0L and 5.7L engines)
1.
Pressure relief valve
2. Spring (184).
3. Spring retaining pin (185).
4. Drive gear and shaft (181).
5. Idler gear (188) in the pump body (180) with the
smooth side of the gear toward the pump cover
opening. Index the marks made during disassem­
bly.
6. Cover (182), gasket (190) (7.4L engines) and
screws (186).
Tighten
• Screws (186) to 9 N-m (80 in. lbs.).
• Turn the driveshaft by hand to check for smooth
operation.
NOTICE: Be careful of twisting, shearing or
collapsing the pipe while installing in the
pump.
(183).
V8 ENGINES 6AS-19
7. Pickup screen and pipe (187) (if removed) (figure
37).
• If the pickup screen and pipe assembly was
removed, it should be replaced with a new part.
Loss of press fit condition could result in an air
leak and loss of oil pressure.
• Mount the oil pump in a soft jawed vise.
• Apply sealer to the end of the pipe.
• Tap the pickup screen and pipe into place,
using J 21882 (5.0L and 5.7L engines), and a
hammer.
• The pump screen must be parallel with the bot­
tom of the oil pan when installed.
8. Oil pump driveshaft (178) and connector (179).

VALVE TRAIN COMPONENTS

PUSHRODS, ROCKER ARMS, BALL, AND NUTS
Clean
• Parts in solvent. Blow dry with compressed air.
• Make sure the oil passages in the pushrods are
clear.
— Rocker arms and balls at their mating surfaces.
These surfaces should be smooth and free from
scoring or other damage.
— Rocker arm areas which contact the valve stems
and the sockets which contact the pushrods.
These areas should be smooth and free of dam­
age and wear.
— Rocker arm nuts or bolts.
• The 5.7L engine uses prevailing torque nuts. At
least 6.2 N.m (55 in. lbs.) torque should be
required to thread the nuts onto the rocker arm
studs. If not, it is possible that the nut(s) could
back off during engine operation, causing loss
of lash and valve train noise.
• The 7.4L engine uses a bolt to retain the rocker
arm, ball and pushrod guide to the cylinder
head.
— Check pushrods for bending. Roll the pushrod on a
flat surface to determine if it is bent. Replace if
necessary.