GMC 4000 Series Service Manual page 311

Sec. 6B
Page 300
TORO-FLOW DIESEL ENGINE
C RANKSHAFT
C O N E
RETAINER
Figure 13— Crankshaft Dam per Retainer Parts
4. Install pulley on damper hub, and install
drive belts.
5. If vehicle is type with fan installed at front
end of crankshaft, install fan hub assembly andfan.
CRANKSHAFT FRONT COVER OIL
SEAL REPLACEMENT
In event of oil leak at crankshaft front oil seal
it is possible to replace the oil seal (located in
engine front cover without removing cover assem ­
bly from engine. Replace the seal as follows:
1 Engine Front Cover
2 Oil Seal Assembly
3 Oil Seal Installer
(J-7879-10)
4 Key
Figure 14— Front Cover O il Seal Installation
G M C S E R V I C E M A N U A L
DAMPER
5 Pulley Installer
Installer Screw
6
7 Crankshaft
Oil Slinger
8
9 Crankshaft Gear
10 Installer Nut
11 Thrust Bearing t
823-2
1. Remove crankshaft damper following the
procedure previously given under "Crankshaft
Damper Replacement."
2. Pry oil seal out of front cover assem bly.
3. Use special installer (J-7879-10) in manner
shown in figure 14, and p ress new oil seal into
bore in cover. Seal lip must point inward toward
crankshaft oil slinger (8, fig. 14). When using in­
staller, turn crankshaft so key is on top. This cen­
ters the tool properly so pressure is applied uni­
formly over outer diameter of seal.
4. Inspect surface on damper hub, with mag­
nifying glass if necessary, to locate any nicks,
burrs, or scratches which could cause rapid wear
at oil seal. When inspection shows surface to be
in poor condition, install a new damper assem bly.
5. Install damper assem bly as previously in­
structed under "Crankshaft Damper Replacement."
ENGINE OIL PAN REPLACEMENT
OIL PAN REMOVAL
1. Clean all dirt and accumulated material
from oil pan attaching bolts and drain plug.
2. Drain oil from oil pan.
3. Remove oil pan bolts and stud nut, then
remove oil pan. Scrape off any portions of gasket
which adhere to oil pan flange or to bolting flange
on cylinder block and engine front cover.
OIL PAN INSTALLATION
1. Use gasket cement to hold new oil pan gas­
ket in place at cylinder block and front cover.
2. Position oil pan at engine and install at­
taching bolts and stud nut.
NOTE: Three of the oil pan bolts are longer
than the others; and these must be installed at rear
of oil pan at reinforcement. These bolts may be
readily identified by internal-external type lock
washers. Other longer (9/16-inch) bolts have spring
type lock washers.
3. Install drain plug with new gasket, then fill
crankcase with engine oil to "FULL" mark on dip
stick.
ENGINE OIL PUMP REPLACEMENT
(Key Numbers Refer to Figure 15)
REMOVAL
1. Remove engine oil pan as previously direc­
ted under "Engine Oil Pan Replacement."
2. Remove two special bolts (7) which attach
oil pump body to cylinder block, then remove oil
pump and the suction tube and screen assembly as
a unit. Oil pump drive shaft (6) will usually dis­
engage from socket in tachometer drive and will
remain with oil pump as it is removed.
3. Remove gasket; clean gasket contact areas
on pump mounting flange and on cylinder block„