GMC C Series 1993, Repair Manual

Page: 175 / 264

V8 ENGINES, GASOLINE 6A2-19
y Measure (Figures 36 and 37)
Tool Required:
J 7872 Dial Indicator (or equivalent)
• Camshaft (75) runout (figure 36). Mount the cam­
shaft in V-blocks or between centers. Using J 7872,
check the intermediate camshaft journal. If runout
exceeds 0.0015 inch, the camshaft is excessively
bent and should be replaced along with the cam­
shaft bearings.
• Camshaft journal out-of-round. Use a micrometer
(figure 37). If the journals are more than 0.001 inch
out-of-round, replace the camshaft.
• Camshaft journal diameter. Use a micrometer (fig­
ure 37). The proper diameter is listed jn “Specifica­
tions.”
CAMSHAFT BEARINGS
Inspect
• Camshaft bearings for scratches, pits, or loose fit in
their bores. Replace the camshaft bearings if nec­
essary.
Figure 36— Measuring Camshaft Run-Out
Figure 37— Checking the Camshaft Journals
A. BEARING TOOL C. NUT
B. PILOT D. PULLER SCREW
Figure 38—Replacing the Inner Camshaft Bearings
Figure 39—Replacing the Outer Camshaft Bearings
Disassemble (Figures 38 and 39)
Tool Required:
J 6098-01 Camshaft Bearing Remover and
Installer
1. Rear camshaft plug.
2. Inner camshaft bearings using J 6098-01 (figure
38).
A. Insert the pilot into the front camshaft bearing
bore.
B. Slide the puller screw, with the nut and washer,
through the pilot.
C. Insert the bearing tool into the inner camshaft
bearing bore, with the shoulder of the tool
against the bearing.
D. Thread the puller screw into the bearing tool.
Make sure enough threads are engaged.
E. Hold the puller screw with a wrench. Turn the
nut with a second wrench to pull the camshaft
bearing from its bore.