Three-Stage Mast
4000 SRM 764
3.
Use the crane to move the intermediate mast
weldment into position over the outer mast weld-
ment.
Fasten the slings to the centers of the
channels to balance the weldment as during re-
moval. Make sure the intermediate mast weld-
ment is at approximately a 30-degree angle with
the bottom load rollers in the notch near the top
load rollers of the outer mast channels. Slowly
lower the intermediate mast weldment and in-
sert it into the outer mast weldment.
4.
Check the clearance of the load rollers and the
strip bearings. Make the necessary adjustments
as described in Mast Adjustments.
5.
With the intermediate mast weldment approx-
imately 152 to 305 mm (6 to 12 in.) out of the
outer mast weldment, install the chain and hose
sheaves. Move the intermediate mast weldment
into the outer mast weldment so the tops of the
main-lift cylinder rods are through the holes
in the intermediate mast channels. Install the
washers and snap rings to fasten the cylinder
rods to the channels.
6.
Use the procedure of Step 3 to install the inner
mast weldment. Check the clearance of the load
rollers and the strip bearings. Make the neces-
sary adjustments as described in Mast Adjust-
ments.
7.
Use the following procedure to install the outer
lift chains between the top of the outer mast
weldment and the inner mast weldment:
a. Slide the inner mast weldment for access to
the chain anchors.
b. Connect a piece of wire approximately 1 m
(3 ft) long to the end of each lift chain. Use
the wire to pull each lift chain into position
between the channels of the inner and inter-
mediate mast weldments. Connect the ends
of the chains to the chain anchors at the bot-
tom of the inner mast weldment. Use new
cotter pins during installation of the chains.
c.
Use the wires to pull the chains up between
the chain sheaves and the top load rollers on
the intermediate mast weldment. Look be-
tween the inner and intermediate mast weld-
ments to see the positions of the lift chains.
If necessary, use a thin screwdriver to move
each lift chain to the inside edge of the inner
mast weldment. Remove the wires.
d. Install the chain, hose, and cable sheaves
as removed during disassembly. Lubricate
the bearings with multipurpose grease dur-
ing installation.
e.
Connect each end of a wire approximately
2 m (6 ft) long to the end of each lift chain.
f.
Pull on the wires to pull the inner mast weld-
ment into the intermediate mast weldment.
Remove the wires from the chains. Connect
each chain to the anchors on the outer mast
weldment. Use new cotter pins during instal-
lation of the chains. If necessary, adjust the
length of the lift chains as described in Lift
Chain Adjustment.
8.
Install a sling near the center of the free-lift
cylinder as during removal. Use a crane to move
the cylinder into position in the inner mast weld-
ment. Install the capscrews, spacers, washers,
and nuts that fasten the shell of the free-lift
cylinder to the inner mast weldment. Install the
snap ring that fastens the bottom of the cylinder
to the mast weldment. If necessary, install the
crosshead assembly to the free-lift cylinder. Ad-
just the cylinder so the cylinder shell is parallel
to the sides of the inner mast weldment ±3.0 mm
(±0.12 in.).
Install the hydraulic lines to the
free-lift cylinder. See Figure 12 or the Diagrams
manual for your truck..
INSTALL
The procedure for installing the three stage masts is
the same as the procedure for the two-stage masts.
See Install for the Two-Stage Mast for the correct
procedure.
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