Chevrolet 1988 Light Duty Truck Repair Manual page 368

6A1-16 2.5 LITER L4 ENGINE
108. C a m s h a ft
Figure 25— Measuring Camshaft Journal Runout
INTAKE AND EXHAUST
MANIFOLDS
igi
Clean
Old pieces of gasket from the gasket surfaces.
L»
Inspect
Manifolds for cracks, broken flanges, etc.
Gasket surfaces for heavy scratches.
CAMSHAFT
In sp ect (Figure 5)
• Cam shaft lobes and journals for scratches, pitting,
scoring, and wear.
• Tim ing gear for damaged or missing teeth.
M easu re (F ig u res 25 th ro u gh 27)
Tool Required:
J 7872 Dial Indicator (or equivalent)
C am shaft runout. M ount the cam shaft between
c e n te rs or in V -blocks. U sin g tool J 7872 (or
e q u iv a le n t), c h e c k th e in te rm e d ia te c a m s h a ft
Figure 26 — Checking the Camshaft Journals
F-01998
Figure 27— Measuring Cam shaft Thrust Plate
Clearance (Camshaft End Play)
journals. If runout exceeds 0.020-inch, the cam shaft
is excessively bent and should be replaced, along
with the cam shaft bearings.
Cam shaft journal out of round. Use a micrometer. If
the journals are more than 0.001-inch out of round,
replace the camshaft.
Cam shaft journal diameter. Use a micrometer. The
proper diam eter is 1.869-inch.
Thrust plate (105) to cam shaft (108) clearance. This
clearance governs cam shaft end play. Use a feeler
gage. The p ro p e r c le a ra n c e is 0.0015-inch to
0.0050-inch. If the clearance is less than 0.0015-inch
replace the spacer ring (106). If the clearance is
more than 0.0050-inch, replace the thrust plate
(105).
❖
D isassem b le (F ig u re 28)
1. Gear (104) from the camshaft.
• Place the cam shaft gear in a press. Support
the cam shaft gear. DO NOT support the thrust
plate.
Figure 28— Removing the Cam shaft Gear