GMC T Series 1994 Repair Manual page 537

3. Inner camshaft bearings using J 33049 (figure 49).
A. Assemble the tool with the pilot engaged in the
front bearing and the pilot flange against the
front face of the block.
B. Slide the puller screw, with nut and washer,
through the pilot.
C. Place the new bearing on the bearing tool. Hold
the bearing tool and bearing against the bearing
bore. Align the bearing oil hole with the oil hole
in the block.
D. Thread the puller screw into the bearing tool
enough to hold the tool and bearing in place.
E. Holding the puller screw with a wrench, turn the
nut with a second wrench to pull the camshaft
bearing into place, flush with the front of the
block web.
F. Remove the puller screw, pilot, and bearing
tool.
Important
• The bearing oil hole on inner camshaft bearings
MUST align with the oil hole in the block located
at the 1 o'clock position. The bearing seam
must be located in the upper half of the block at
approximately 11 o' clock.
. New rear camshaft plug.
A. Coat the camshaft plug with sealer (Loctite 592
or equivalent).
B. Install the plug flush to 0.80-mm (1/32-inch)
deep.
T IM IN G CH AIN, SPROCKETS
AND TIM IN G GEARS
Inspect
A. Sprockets for chipped teeth and wear.
B. Timing chain for damage.
• It should be noted that e xcessively worn
sprockets will rapidly wear a new chain. Like­
wise, an excessively worn chain will rapidly
wear a new set of sprockets.
C. Timing gears on the injection pump and camshaft
for wear and broken teeth.
Important
If the timing chain and sprockets or gears are
replaced, it will be necessary to re-time the engine.
Refer to " Front Cover Installation."
FRONT COVER
Clean
Old sealer from the sealing surfaces.
L*
Inspect
Baffle for damage.
Front cover for cracks and damage to the sealing
surfaces.
Disassemble
❖
Front crankshaft seal. Pry the seal out with a large
screwdriver.
Assemble
Tool Required:
J 22102 Seal Installer
A. Front crankshaft seal. Use J 22102. The open end
of the seal must face inside the cover.
B. Coat the seal lips with grease.
Important
If a new front cover is installed, the engine must be
re-timed; refer to " Front Cover Installation."
COOLANT PUMP
imp
Clean
The coolant pumps used with the serpentine belt sys­
tem all rotate counterclockwise (CCW). The pump bod­
ies are the same except for the bypass hose fitting. The
P and G van chassis coolant pump use a 5/8-inch O.D.
bypass fitting. CK models use a 1-inch O.D. fitting. The
1-inch fitting is used with a blocking bypass thermostat.
IJJl] Clean
• Old gasket from the gasket surfaces on the coolant
pump and coolant pump plate.
Important
• Do not immerse the pump in solvent. The sol­
vent may enter the pump's permanently lubri­
cated bearings, dissolve the bearings' lubricant
supply, and cause premature bearing failure.
L *
Inspect
• Coolant pump shaft for roughness and end play. If
the shaft does not turn smoothly, or if there is
excessive end play, replace the coolant pump.
• Coolant pump body at the drain hole. If there is
evidence of coolant leakage, the coolant pump
shaft seal is leaking and the coolant pump should
be replaced.
• Coolant pump plate for damage.
OIL PAN AND ROCKER ARM
COVERS
Clean
• Parts in solvent. Remove all sludge and varnish.
• Old sealer from the sealing surfaces.