JLG 1500SJ Service Manual - Manual (Page 324)

SECTION 4 - BOOM & PLATFORM
4-78 – JLG Lift – 3121262
4.16 WIRE ROPE TENSIONING ADJUSTMENT
ANY TIME THE WIRE ROPE TENSIONING HAS BEEN ADJUSTED,
BOOM CALIBRATION SHOULD BE PERFORMED IMMEDIATELY
AFTERWARD.
Before adjusting wire rope tension, the boom sections
must be in the proper position as shown in Figure 4-22.,
Wire Rope Tensioning. This is so the wire ropes are equal-
ized on both sides of the sheaves and are seated properly
in the sheave grooves. This is necessary for proper ten-
sioning of the wire ropes.
This section covers the two major operations in tensioning
the wire ropes which are as follows:
• Positioning the boom sections (so that proper tension-
ing can be achieved).
• Tensioning the wire rope.
Boom Section Re-Positioning
NOTE: Because the Outer Mid Boom is used to control the
movement of the Fly Boom, any repositioning of the
Outer Mid Boom section will also affect the position
of the Fly Boom section. Correctly position the Outer
Mid Boom before repositioning the Fly Boom.
NOTE: Use the Telescope function of the machine to posi-
tion the boom sections. Do not use the wire rope
adjustment nuts to position the booms. This may
cause damage to the wire rope adjustment threads.
1. Ensure the machine is placed on firm, level ground.
2. Before making any adjustments, position the boom
assembly in the fully retracted position.
3. Take preliminary measurements of the position of
each boom section and compare them to Figure 4-
22., Wire Rope Tensioning. If the measurements fall
within the tolerances in the figure, proceed to Wire
Rope Tensioning in this section.
PROPER BOOM POSITIONS DO NOT MEAN THAT THE WIRE ROPE
TENSIONS ARE CORRECT.
If the measurements do not fall within the tolerances in
Figure 4-22., Wire Rope Tensioning, adjust the booms
using the re-positioning procedures that follow.
INNER MID BOOM SECTION REPOSITIONING
The inner mid section of the boom is positioned by the
hydraulic cylinder. No adjustments can be made to this
section. The wire ropes within the assembly only control
the movement of the Outer Mid Boom and Fly Boom sec-
tions.
OUTER MID BOOM SECTION REPOSITIONING
If the Outer Mid Boom falls within the dimension and toler-
ance of Figure 4-22., Wire Rope Tensioning, proceed to
the Fly Boom Section Positioning procedure in this sec-
tion. If the Outer Mid Boom section is outside of the toler-
ance as shown, perform the following procedure.
1. Extend the boom assembly so the platform moves 5
to 6 feet (1.5 to 1.8 m) from the fully retracted posi-
tion.
2. Remove any covers necessary to access the wire
rope adjustment nuts.