Camshaft; Camshaft Bearings; Timing Chain And Sprockets; Front Cover - GMC 1990 Light Truck Repair Manual

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

CAMSHAFT

Important
• Whenever the camshaft needs to be replaced, a
new set of lifters must also be installed.
Inspect
Camshaft lobes and journals for scratches, pitting,
scoring, and wear.
Measure
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

L*
Inspect
Sprockets for chipped teeth and wear.
Timing chain for damage.
It should be noted that excessively worn sprockets
will rapidly wear a new chain. Likewise, 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/e-inch), from the damper,
replace the chain.
CRANKSHAFT SPROCKET REPLACEMENT
Remove or Disconnect (Figure 20)
Tool Required:
J 5825-A Crankshaft Sprocket Puller
1. Crankshaft sprocket using J 5825-A.
2. Key (if necessary).
-6
Figure 20—Replacing the Crankshaft Sprocket
-n - Install or Connect (Figure 20)
Tool Required:
J 5590, Crankshaft Sprocket Installer
1. Key (if removed).
2. Crankshaft sprocket using J 5590.

FRONT COVER

Clean
Old gasket from the gasket surfaces.
Inspect
• Timing tab marker for damage.
• Front cover for damage, dents, or cracks.
Remove or Disconnect
• Oil seal from the front cover.
— Pry the seal out with a large screw driver.
B-07891