Camshaft - Chevrolet 1988 Light Duty Truck Repair Manual

6A4-16 4.8 LITER L6
A. In d ic a to r
B. C h e c k in g F ix tu re
182. C a m s h a ft
Figure 26— Measuring Camshaft Journal Runout
*
A ssem b le (F ig u re 4)
1. Gasket (36) to the exhaust manifold (37).
2. Intake manifold (31) and exhaust manifold (37).
3. Nuts (32), bolts (39) and washers (40). Leave the
fasteners hand-tight until the manifold to cylinder
head bolts are to rq u e d . R efer to
Exhaust Manifold Installation."

CAMSHAFT

Im p o rtan t
• W henever the cam shaft needs to be replaced, a
new set of hydraulic lifters must also be installed.
] ? \ In sp ect (F ig u res 5, 26, 27, and 28)
— Cam shaft (182) lobes and journals for scratches,
pitting, scoring, and wear.
— Tim ing gear (94) for damaged or missing teeth.
m
M easu re (F ig u re s 26, 27, and 28)
Tool Required:
J-7872 Dial Indicator (or equivalent)
Figure 27— Checking the Camshaft Journals
B-04578
Figure 28— Measuring Cam shaft Thrust Plate
— C a m s h a ft (182) ru n o u t (fig u re 26). M o u n t the
' Intake and
cam shaft between centers or in V-blocks. Using
J-7872 (or e q u iv a le n t), c h e c k the in te rm e d ia te
cam shaft journals. If runout exceeds 0.020-inch, the
c a m s h a ft is e x c e s s iv e ly b e n t and s h o u ld be
replaced, along with the cam shaft bearings.
— Cam shaft journal out of round. Use a microm eter
( fig u r e
1.8677-1.8697-inch.
— Thrust plate (94) to cam shaft (182) clearance. This
clearance governs cam shaft end play. Use a feeler
g a g e
0.003-0.008-inch. Excessive clearance indicates that
the thrust plate is worn and should be replaced, as
outlined following:
C AMSHAFT GEAR AND
THRUST PLATE REPLACEMENT
D isassem b le (F ig u res 5 and 29)
1. Cam shaft gear (94).
Figure 29 — Removing the Camshaft Gear
Clearance (Camshaft End Play)
2 7 ). T h e p ro p e r
( fig u r e 2 8 ). P ro p e r
d ia m e te r is
c le a ra n c e is