Rear Crankshaft Oil Seal Installation; Camshaft, Timing Chain And Sprocket Installation; Front Cover Installation; Torsional Damper Installation - GMC 1990 Light Truck Repair Manual

6A3-18 4.3 LITER V-6
A. Rear o f Block
80. Screw
81. Nut
82. Retainer
83. Stud
83
84. Gasket
Figure 27—Rear Crankshaft Oil Seal Retainer
Installation
2. Seal retainer (82).
3. Screws (80) and nuts (81).
^X\ Tighten
• Screws and nuts to 15.3 N-m (135 in. lbs.).
REAR CRANKSHAFT OIL
SEAL INSTALLATION
■n- Install or Connect (Figure 28)
Tool Required:
J 35621 Seal Installer
• Rear crankshaft oil seal.
• Lubricate the inner and outer diameter of the
seal with engine oil.
• Install the seal on J 35621.
• Position J 35621 against the crankshaft.
Thread the attaching screws into the tapped
holes in the crankshaft.
Figure 28—Installing the Rear Crankshaft Oil Seal
• Tighten
screwdriver. This will ensure that the seal is
installed squarely over the crankshaft.
• Turn the handle until it bottoms.
• Remove J 35621.
CAMSHAFT, TIMING CHAIN
AND SPROCKET INSTALLATION
-► + Install or Connect (Figures 29, 30, and 31)
• Coat the camshaft lobes and journals with a high
quality engine oil supplement (GM Engine Oil
Supplement or equivalent).
1. Two or three 5/ie-18 bolts 100-125 mm (4-5 inches)
long into the camshaft threaded holes. Use these
F-02922
bolts to handle the camshaft.
2. Camshaft to the engine (figure 30). Handle the
camshaft carefully to prevent damage to the
camshaft bearings.
3. Thrust plate (87) and screws (88).
Tighten
• Screws to 11.9 N-m (105 in. lbs.).
4. Camshaft sprocket and timing chain.
Important
• Line up the timing marks on the camshaft
sprocket and crankshaft sprocket (figure 31).
5. Camshaft sprocket bolts.
Tighten
• Camshaft sprocket bolts to 28 N-m (21 ft. lbs.).

FRONT COVER INSTALLATION

-n - Install or Connect
1. Front cover gasket to the front cover.
• Use gasket cement to hold the gasket in place.
2. Front cover to the engine.
3. Front cover bolts and reinforcements.
Tighten
• Front cover to block bolts to 13.6 N-m (120 in.
lbs.).
TORSIONAL DAMPER
Install or Connect (Figure 32)
Tool Required:
J 23523-E, Torsional Damper Puller and
B-07886
Installer
1. Crankshaft key (if removed).
the screws securely
INSTALLATION
with a