Single-Reach Scissor Arms
4500 SRM 971
Single-Reach Scissor Arms
REMOVE AND DISASSEMBLE
NOTE:
The reach assembly must be in the fully-ex-
tended position.
For the following procedures, see Figure 10.
WARNING
There are pinch points on the reach car-
riage that can cause an injury.
Use clamps
and blocks to prevent the scissor arms from
moving. Install the clamps and blocks at the
channels of the rear frame to make sure that
the load bearings cannot move in the channel.
See Figure 7.
WARNING
Be careful when removing or installing snap
rings.
These snap rings are large and can
come loose during removal or installation with
enough force to cause an injury. Always use
the correct snap ring pliers, and wear eye and
face protection during removal or installation.
NOTE:
Use safety chains on the rear frame and mast
weldments to keep the rear frame and mast weld-
ments from moving. Install the safety chains as de-
scribed in Safety Procedures When Working Near
Mast in this section.
1.
Remove the front frame as described in Reach
Assembly Outer Frame. Remove the snap rings
and hose sheaves at the scissor arm weldment.
Fasten the cable and hoses at the rear frame so
that they are not damaged.
2.
Use a crane and chains or slings as a support for
the scissor arm weldment. Do not damage the
hose sheave mount.
WARNING
The points between the scissor arms and the
front frame are pinch points and can cause an
injury.
DO NOT put your finger in the hole
when you remove the pins. Use the brass drift
to remove the pins.
3.
Remove the shoulder bolt and nut. Use a drift to
remove the pins that fasten the rod ends of the
reach cylinders to the scissor arm weldment. Use
wire to hold each reach cylinder and their hoses
in a position for clearance as the load bearings
move. Remove the bushings from the mounts.
WARNING
The load bearings and scissor arms can move
and cause an injury when the clamps and
blocks at the load bearings are removed. Make
sure the crane is in a position to prevent move-
ment of the scissor arms as the clamps and
blocks are removed.
4.
Carefully remove the clamps and blocks at the
load bearings on the channels of the rear frame.
Slowly move the scissor arms to align the load
bearings with the removal notch in the rear
frame. Raise the scissor arm weldment and the
scissor arms to move the load bearings out of the
rear frame.
NOTE:
Install labels for each set of shims and the
load bearing on the scissor arms for correct assembly
during installation of the scissor arms. When new
load bearings are installed, the shim arrangement
will normally be the same or similar. Remove the
load bearings and shims.
WARNING
The scissor arms are heavy and can cause an
injury if allowed to fall. Have another person
help you support the scissor arm during re-
moval and installation.
5.
Install labels for correct installation of the right-
hand or left-hand scissor arms. Carefully remove
the three capscrews, the lockwashers, the end
cap, and the two thrust washers at the center
pivot for the scissor arm and scissor arm weld-
ment. Hold the scissor arm and carefully slide it
off the bushing and stub shaft of the scissor arm
weldment. Remove the bushing and the other
two thrust washers. Remove the other scissor
arm following this same procedure.
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