4500 SRM 971
Double-Reach Scissor Arms
Legend for Figure 11
1.
INNER ARM WELDMENT
2.
BEARING
3.
BUSHING
4.
BUSHING
5.
WASHER
6.
OUTER ARM ASSEMBLY (LH)
REAR
7.
MECHANISM ARM
8.
MAIN BUSHING
9.
OUTER ARM ASSEMBLY (RH)
REAR
10. ROD END
11. CYLINDER ASSEMBLY
12. PIN - ROD END
13. LUBE FITTING
14. INNER ARM WELDMENT
15. SHIM
16. OUTER ARM ASSEMBLY (LH)
FRONT
17. OUTER ARM ASSEMBLY (LH)
FRONT
18. END CAP
19. END CAP - CENTER
20. LOCKWASHER
21. CAPSCREW
22. BEARING
23. ROLLER - FRONT ARM
24. WASHER
25. SCREW
26. EXTEND CYLINDER (LH)
27. FITTING WITH O-RING
28. EXTEND CYLINDER (RH)
29. FITTING WITH O-RING
30. SHEAVE
31. RETAINING RING
32. SHIM
33. WASHER
34. PIN
35. WASHER
36. WASHER
37. SCREW
38. NUT
39. CABLE CLAMP
40. WASHER
41. CAPSCREW
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.
NOTE:
Install labels for correct installation of the
right-hand or left-hand scissor arms.
4.
Carefully remove the three capscrews, the lock-
washers, the end cap, and the two thrust washers
at the center pivot for scissor arm 1A and scis-
sor arm weldment A. Hold scissor arm 1A and
slide it off the bushing and stub shaft of the scis-
sor arm weldment. Remove the bushing and the
other two thrust washers at the center pivot. Re-
move the bushing and the other two thrust wash-
ers from the stub shaft at the end of the scissor
arm. Remove scissor arm 2A following this same
procedure.
5.
Slowly lower scissor arm weldment A so it hangs
from the ends of scissor arms 1B and 2B. Move
the crane and chains or slings so they are a sup-
port for the scissor arm weldment B.
WARNING
The points between the scissor arms and the in-
ner frame are pinch points and can cause an in-
jury. Do NOT put your finger in the hole when
you remove the pins. Use the brass drift to re-
move the pins.
6.
Remove the shoulder bolts in the rod ends of the
reach cylinders (Figure 15). Use a drift to remove
the pins that fasten the rod ends of the reach
cylinders to scissor arm weldment B. Use wire to
hold each reach cylinder and hoses in a position
for clearance as the load bearings move.
WARNING
The load bearings and scissor arms 1B and 2B
can move and cause an injury when the clamps
and blocks at the load bearings are removed.
Make sure the crane (Step 5) is in a position
to prevent movement of the scissor arms as the
clamps and blocks are removed.
7.
Carefully remove the clamps and blocks at the
load bearings on the channels of the inner frame.
Slowly move scissor arm weldment A to align the
load bearings of scissor arms 1B and 2B with the
removal notch in the inner frame. See Figure 11.
Use the crane to move the scissor arm assembly
so the load bearings are out of the inner frame.
NOTE:
Install labels for each set of shims and the
load bearing on scissor arms 1B and 2B. Install the
labels 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.
NOTE:
Correct placement of shims is critical for the
operation of the reach mechanism. Unless the shims
are installed correctly the reach mechanism will not
operate.
8.
Carefully lower the crane so the scissor arm as-
sembly "retracts" as the ends of the scissor arms
move down the outside of the channel. Do not
damage the stub shafts for the load bearings.
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