GMC 4000 Series Service Manual page 67

Sec. 1
Page 60
TILT CAB
Figure 2 5 — Vent W in d o w Disassembled
3. After obtaining proper tension, install ac­
cess trim panel.
DOOR VENT GLASS REPLACEMENT
REMOVAL
1. Remove sm all access panel from inner side
of door below vent window.
2. At bottom of vent glass (fig. 23), place hand
to catch vent friction components, then remove
screw from friction clamp. Slide clamp, friction
bushing, and flat steel washer from vent shaft.
3. At top of door through sm all access open­
ing (see inset, fig. 23), turn vent upper pivot screw
from vent frame.
NOTE: Screw need not be removed completely,
just enough to become disengaged from vent glass
channel.
4. Remove three screws which attach division
channel to vent channel just below vent latch. Using
a screwdriver, pry down on vent channel as shown
in figure 24, which will cause upper part of channel
to become disengaged from pivot screw. Rotate
g lass channel lower pivot shaft up out of vent
channel.
5. Remove two screw s which attach glass up­
per channel to glass lower channel (fig. 25).
6. Apply gasoline on vent glazing rubber to
soften old rubber. When rubber softens sufficiently,
separate upper and lower glass channels, then re­
move old glass.
INSTALLATION
1. Thoroughly clean inside of glass channels
G M C S E R V I C E M A N U A L
to remove old glazing rubber, rust, or other for­
eign matter.
away from glass) around edge of glass. Press
glass with glazing rubber into lower channel, then
press upper channel over top of glass. Make sure
channels are firmly seated, then install two small
screw s which attach channels together (fig. 25).
of channels and along sides of channel each side of
glass. As required, seal cracks at latch bracket.
hole of vent frame as shown in figure 24. Through
sm all access hole at top of door, install vent upper
pivot screw. Install three screws which attach
bracket of vent channel to glass division channel
just below vent latch.
bushing, and friction clamp on vent lower channel
pivot shaft, positioned as shown in figure 23.
washer is positioned properly to act as a stop of
vent when it is in full open position. Attach friction
clamp to vent lower frame with screw. Tighten
screw to obtain two to four pounds torque while
moving vent window from a ten-degree to a full-
open position. Use either a push or pull type spring
scale positioned at rear edge of glass.
strip around perimeter of door. Figure 26 shows
view of weatherstrip installed at retainer.
any rubber or adhesive material which may have
become bonded to door surface.
2. Position new glazing rubber (soapstone side
3. If necessary, trim glazing rubber at ends
4. Insert pivot stud of vent lower channel into
5. Install special flat washer, nylon friction
NOTE: Make sure that tab on special flat
6. Install access panel to inner side of door.
DOOR WEATHERSTRIP
REPLACEMENT
1. Remove screw-retained clips from weather­
2. Pull weatherstrip from door, then scrape