GMC 4000 Series Service Manual page 283

Sec. 6A
Page 272
GASOLINE ENGINES
Figure 2 4 — Rem oving Crankshaft Dam per
1. Coat front seal contact area (on damper
hub) with engine oil.
2. Install damper as follows:
a. DRIVE ON TYPE (Without Retaining Bolt).
(1) Attach damper installer Tool (J-22197) to
damper. Tighten fingers of tool to prevent
inertia weight from moving (fig. 25).
(2) Position damper on crankshaft and drive
into position until it bottoms against crank­
shaft gear (fig. 25). Remove installer tool.
b. PULL ON TYPE (With Retaining Bolt).
(1) Use a 7 /16 "-20 x 4" bolt, nut, and washer
or special installer (J-21058) (fig. 26) to
pull torsional damper onto crankshaft. If
tool is used, hold bolt with wrench, then
turn threaded sleeve to force hub onto
crankshaft.
Figure 2 5 — Installing D riv e -O n Type C rankshaft D am per
G M C S E R V I C E M A N U A L
Figure 2 6 — Installing Pull-On Type Crankshaft Dam per
sion gauge.
ley and belt.
IATOR AND SURGE TANK (SEC. 13) of this manual.
REMOVAL
er as directed previously.
screw s, remove cover and gasket.
INSTALLATION
case front cover. If oil seal requires replacing,
follow instructions given later under appropriate
heading.
Tool (J-21742) in crankcase front cover seal (fig.
27).
Attach new oil pan seal at cover lower flange.
used to align front cover so that crankshaft hub or
INSTALLER T O O L
CAUTION: Install bolt in crankshaft
with sufficient thread engagement (min.^").
(2) Remove bolt, nut, and washer or tool, then
install retaining bolt and torque to "Speci­
fications."
3. Install fan belt and adjust using strand ten­
4. If so equipped, install accessory drive pul­
5. Install radiator core as directed in RAD­
6. Connect radiator hoses.
7. Fill cooling system and check for leaks.
CRANKCASE FRONT COVER
A N D OIL SEAL
1. Remove oil pan.
2. Remove crankshaft pulley and hub or damp­
3. Remove crankshaft front cover attaching
1. Clean gasket surfaces on block and crank­
2. Install centering Tool (J-0966) or centering
3. Cement cover gasket in place on block.
NOTE: It is important that centering tool be