Oshkosh JLG 1500SJ, Service And Maintenance Manual

Page: 326 / 706

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 CALI-
BRATION SHOULD BE PERFORMED IMMEDIATELY AFTERWARD.
Before adjusting wire rope tension, the boom sections must
be in the proper position as shown in Figure 4-21., Wire Rope
Tensioning. This is so the wire ropes are equalized on both
sides of the sheaves and are seated properly in the sheave
grooves. This is necessary for proper tensioning 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 tensioning
can be achieved).
• Tensioning the wire rope.
Boom Section Re-Positioning
NOTE: Because the Outer Mid Boom is used to control the move-
ment 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 position 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 4-21., Wire
Rope Tensioning. If the measurements fall within the tol-
erances 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
4-21., 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 sec-
tion. The wire ropes within the assembly only control the
movement of the Outer Mid Boom and Fly Boom sections.
OUTER MID BOOM SECTION REPOSITIONING
If the Outer Mid Boom falls within the dimension and toler-
ance of Figure 4-21., Wire Rope Tensioning, proceed to the Fly
Boom Section Positioning procedure in this section. If the
Outer Mid Boom section is outside of the tolerance 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 position.
2. Remove any covers necessary to access the wire rope
adjustment nuts.