GMC PD-4103 Maintenance Manual page 34

GM COACH MAINTENANCE MANUAL
Sec. 3
Page 35
a sharp chisel, marking center of rivet with a
center punch, then drilling out rivet with a drill
slightly smaller than body of rivet. Rivet can also
be driven out with punch, instead of being drilled
out, depending upon type and size of material riv-
eted. If rivet is large, first cut a groove across
center of rivet head with a cape chisel before
cutting off head with a flat chisel.
WELDING
Refer to note, earlier in this section, regard-
ing•welding of structural parts.
Shielded arc welding is recommended as heat
of weld is localized and burning of material min-
imized with this method. When welding a cut
member, fill or weld cut completely. Welding
rods should be of substantially same material as
parts to be welded.
SEALING
When replacing front, side, rear panels, and
particularly roof panels, special attention should
be given to proper sealing of joints. Use of the
sealing and caulking compound, listed at end of
this section, is recommended whenever necessary
to exclude water, dust, cold, and air.
DINGING AND FINISIDNG
Paint is quickly scuffed off sharp dents leaving
bare metal exposed to corrosion. Importance of
proper metal finishing to produce a fairly smooth
surface should, therefore, not be underestimated.
Application of hammer directly to panel tends to
stretch the metal unnecessarily. Whenever possi-
ble a spoon should be used when bumping a panel.
Repair damaged panels by forcing outward in di-
rection opposite to force which caused damage. In
this way metal strains, set up when damage oc-
curred, are relieved.
DOORS AND CONTROLS
Vehicle has two passenger doors -- front en-
trance and emergency. Both doors are sedan type,
hinged at front, and open outward.
FRONT ENTRANCE DOOR
Entrance door is hand-operated type, controlled
by door operating mechanism connected between
dash and door. Mechanism is so designed that
door is locked firmly in either fully open, or fully
closed position. Door, however, can be opened
from outside vehicle by pressing door release rod
knob, located in front panel below windshield.
Door requires little maintenance other than
lubrication of hinges and operating mechanism.
Mechanism is adjusted by disconnecting door op-
ening rod from door, loosening socket locknut,
then turning socket, to shorten or lengthen rod.
BODY
Stepwell Support
Channel Front Support Panel
Seal Retainer
/ Front Support Angle
Support Channel
Gusset
Support Channel
/
Bracket
t/!'""~Front Track
~~
Track Ball
Track Front
Clip
TP-6336
Figure 4-Retracting Step
Whenever door opening rod is adjusted, door op-
ening and closing stop screws should also be ad-
justed. Properly adjusted mechanism will swing
over center and lock door firmly in both fully
closed and fully open position. In either position,
it
should not be possible to move the door unless
handle is first moved out of locking position.
Retracting Step (Fig. 4)
Retracting step operates in conjunction with
entrance door. Connected to door by operating
rod, step slides outward as door is opened. In
retracted position, clips on step engage springs on
shield to prevent rattling of step.
Retracting step requires no maintenance, other
than occasional oiling of clevis pin on operating
rod.
When necessary to remove step, remove clevis
pin at door. Open door fully; then pull step straight
outward from coach. Reach .into pan and remove
three balls each from forward and reverse tracks.