TRUCK SERVICE MANUAL
inner race, press bearing onto shaft until Inner race
Note: Lubricate bearings with SAE 30 lubricating oil
bottoms on flange of shaft.
2. Supporting bearing on outer race, press pulley onto
3. Coat lip of seal (2) with lubricating oil, slide shaft (1)
bearing until pulley bottoms; install snap ring in groove.
through seal and bearing. Do not damage seal.
3. Using ST-658 Mandrel, install new oil seal. Lubricate
4. Place bearing spacer (7) over shaft and install front
"O" ring and lip of seal, position "O" ring in groove of
5. Install washer (if used) and locknut (9). Tighten nut to
4. Install idler shaft spacer over shaft and "O" ring, press
150 ft-lbs [20.7 kg m] torque.
into position through seal until spacer bottoms against
6. Rotate fan hub and check end clearance. Fan hub
bearing inner race.
must rotate freely, end clearance must be 0.003 to 0.010
5. Install new grease fitting, if required, fill 1/2 to 2/3 full
inch [0.08 to 0.25 mm].
with grease. See Group 18 for type grease.
7. Place lubricated "O" ring (11) on retainer (10) and
6. Position idler assembly to water pump housing.
press or drive into pulley bore.
Secure finger tight with flatwasher and nut. Install
8. Install fan spacer (12) with cupped side next to
adjusting screw. Do not tighten.
9. Position fan hub so that drain hole is horizontal, filler
FAN AND FAN HUB
hole must either be at top of hub or opposite drain hole.
Check fan blades for bends, dents or cracks; clean
Fill with grease lubricating oil to level of drain hole.
disassembled part as outlined in Group 0, Engine
10. Install pipe plugs, tighten to 5 to 7 ft-lbs [0.7 to 0.10
Tapered Roller Bearing Type With Bearing Spacer
THERMOSTAT AND HOUSING
Thermostats are not subject to repair, but should be
DISASSEMBLY AND INSPECTION
checked to make sure they are opening and closing at
1. Remove pipe plugs (6, Fig. 8-4), drain oil from hub.
the proper temperatures.
2. Remove spacer (12), "0" ring retainer (10), locknut (9)
and washer (if used).
DISASSEMBLY AND INSPECTION
3. Remove pulley (5) from shaft, remove front bearing
(3) and spacer (7) from pulley.
Remove water outlet connection(s), thermostat
4. Remove seal (2) and rear bearing (3), discard seal.
housing, and thermostat(s). Remove thermostat seal
5. Inspect bearings, races, and fan hub shaft for
roughness, pitting and wear.
6. If shaft is damaged in seal mating area it can be
2. Check thermostat to see if it opens and closes at the
cleaned up by'using 240 grit or fine emery paper.
7. Bearing races (4) may be removed with a flat punch
a. Immerse thermostat and thermometer in water.
by striking, from the back side, alternately from side to
b. Heat water to operating temperature, allow time for
side until the race drops out.
thermostat metal to stabilize with water temperature, then
8. If bearing races are removed, inspect snap rings (8).
compare thermostat operation with thermometer.
Do not remove snap rings unless damaged.
c. Low-range thermostats start opening at 160 deg. F
9. Inspect parts for chips, cracks, wear or distorted
[71 deg. C] and are fully open at 175 deg. F [79 deg. C]
threads. Replace all unserviceable parts.
d. Intermediate thermostats start opening at 175 deg. F
[79 deg. C] and are fully open at 185 deg. F [85 deg. C]
1. If removed, install new snap rings (8) (position into
grooves with hammer handle). Press in bearing races
(4), beveled side out, until races "bottom" against snap
2. Position rear bearing (3) in race (4) and press seal (2)
into pulley bore until flush. (Lip of seal toward bearing.)