GMC 4000 Series Service Manual page 69

Sec. 1
Page 62
TILT CAB
Figure 2 9 — Lifting Sling Attached to Cab
CAB REMOVAL
1. Disconnect battery ground strap.
2. On vehicles with air brakes, exhaust air
supply from air tank at drain fitting. Remove bump­
er (with attached air tank, if used).
3. Open heater temperature control on dash to
full open position, and drain radiator. Disconnect
heater hoses at cab connections.
4. Disconnect accelerator linkage and steer­
ing flexible coupling, marking for later alignment.
Disconnect brake lines and clutch line.
5. Disconnect speedometer cable and a lle le c -
Figure 3 0 — M o u n t in g at C a b Rear Support
G M C S E R V I C E M A N U A L
trie connectors that junction cab with the chassis.
Remove cab-to-chassis ground straps.
ITEMS IN CAB BEFORE TILTING. PLACE SHIFT
LEVER IN NEUTRAL AND THE HAND BRAKE IN
FULL-APPLIED POSITION.
29) to cab with doors partly open (lifting cab with
doors closed will disturb door alignment later).
approximately 45° to the unloaded position of cab
mounting torsion bar (refer to preceding caution)
and suspend safely there. While cab is in this posi­
tion, insert a pry bar in between cab right support
and cab sill. Remove three forward bolts, lock
washers and nuts from cab right support to sill
brackets (B, fig. 30). Use pry bar to a ssist in re­
moving bolts. Disconnect check link at right side
of cab.
catch hole in cab rear support (fig. 31), then with
aid of assistant, lower cab until catch at bottom of
cab rests on block. This will prevent engagement
of cab hold-down catch. Remove two retaining bolts
from torsion bar at cab left support and remove
support cap. Raise cab slightly, and remove rear
mounting bolt (C, fig. 30) attaching right support
to sill brackets.
anism, then forward and up to clear shift control
panel. Figure 32 shows cab and chassis disconnect
points.
move chainfall and lifting sling.
if desired.
with doors slightly open (fig. 29).
Figure 3 1 — Rear H o ld -D o w n Catch on W oo d Block
NOTE: REMOVE OR SECURE ALL LOOSE
6. Attach a suitable padded lifting sling (fig.
7. Using aid of assistant and hoist, tilt cab
8. Place a short piece of wood 2" x 4" over
9. Raise cab slightly to clear cab lift mech­
10. Lower cab onto suitable blocks, then re­
NOTE: Left support can be removed from cab,
CAB INSTALLATION
1. Install lifting sling and chainfall to cab