GMC 4000 Series Service Manual page 457

Sec. 7B
Page 446
TRANSMISSION ON-VEHICLE SERVICE
Figure 2 — Replacing Rear Oil Seal (Typical)
17. If necessary, adjust clutch or transm is­
sion control linkage to achieve proper trans­
mission operation.
REAR OIL SEAL REPLACEMENT
The oil seal used at the rear of Corporation
or New Process transm issions can be replaced
without removing the transm ission from the vehi­
cle. Replace rear oil seal as follows:
REMOVAL
1. Drain lubricant from transmission.
2. Disconnect propeller shaft from trans­
mission as described in " PROPELLER SHAFTS"
G M C S E R V I C E M A N U A L
(SEC. 4D) of this manual.
m ission as described in " PARKING BRAKE"
(SEC. 5C), when used.
speedometer driven gear from mainshaft rear
bearing cap.
the output yoke or companion flange nut. Pull out­
put yoke or companion flange off the mainshaft.
and gasket. Discard gasket.
rear bearing retainer. Discard oil seal.
INSTALLATION
sealing cement. Install oil seal in rear bearing
retainer using tool (J-3154-04). Drive seal flush
with outside of rear bearing retainer, being care­
ful not to damage seal (see fig. 2).
rear bearing retainer and oil seal assembly with
a new gasket to the transmission.
screw s firmly.
mainshaft. Using a flange or yoke holding tool,
install retaining nut. Torque the retaining nut as
follows:
Transmission
SM465 ...........................................
NP435 ..........................................
NP540 ..........................................
3. Remove parking brake from rear of trans­
4. Disconnect speedometer cable and remove
5. Using flange or yoke holding tool remove
6. Remove mainshaft rear bearing retainer
7. Using tool (J -3154-04), drive oil seal from
1. Coat outer diameter of new oil seal with
2. Clean all gasket surfaces, then install the
3. Install output yoke or companion flange on
Retaining Nut-Torque
Tighten cap-
90-120 Ft.-Lbs.
125-150 Ft.-Lbs.
125-150 Ft.-Lbs.