Camshaft; Camshaft Bearings; Timing Chain And Sprockets; Front Cover - GMC 1989 Light Duty Truck Repair Manual

6A2-14 2.8 LITER V-6
Figure 19—Checking the Camshaft Journals

CAMSHAFT

Im portant
Whenever the camshaft needs to be replaced, a
new set of lifters must also be installed.
Inspect
13
Camshaft lobes and journals for scratches, pitting,
scoring, and wear.
M easure
Camshaft journal diameter (figure 19). The proper
diameter is listed in " Specifications."

CAMSHAFT BEARINGS

Refer to GENERAL ENGINE MECHANICAL (SEC. 6A)
for replacement procedures.

TIMING CHAIN AND SPROCKETS

Inspect
e
Sprockets for chipped teeth and wear.
Timing chain for damage.
It should be noted that excessively worn sprockets
w ill ra p id ly w ea r a new c h a in . Like w ise , an
excessively worn chain will rapidly wear a new set of
sprockets.
Timing chain for wear.
— If the chain can be pulled out more than
9.5 mm (3/s-inch), from the damper,
replace the chain.
CRANKSHAFT SPROCKET REPLACEMENT
Rem ove or D isconnect (Figure 20)
Tool Required:
J 5825-A Crankshaft Sprocket Puller
1. Crankshaft sprocket using J 5825-A.
2. Key (if necessary).
Figure 20— Replacing the Crankshaft Sprocket
-►*- Install or C onnect (Figure 20)
Tool Required:
J 5590, Crankshaft Sprocket Installer
1. Key (if removed).
2. Crankshaft sprocket using J 5590.

FRONT COVER

JQ|
Clean
Old gasket from the gasket surfaces.
L 1
Inspect
• Timing tab marker for damage.
• Front cover for damage, dents, or cracks.
|<">| R em ove or D isconnect
• Oil seal from the front cover.
— Pry the seal out with a large screw driver.
B-07891