JLG 9MP Service Manual - Manual (Page 59)

SECTION 5 - MAST COMPONENTS
3121163 – JLG Lift – 5-15
15. Assemble chain sheaves on cylinder anchor block
(attached to cylinder rod end) and attach to mast
section-2 using following steps;
a. Insert sheave pin through anchor block and cyl-
inder rod on cylinder rod end.
b. Load three 1" flat washers onto the sheave pin
on each side of the anchor block.
c. Place sheave wheels (for #444 chain) on sheave
pin, one each side of anchor block.
d. On the outside of each sheave wheel, place 2
flat washers, a roll pin (into the slot in each end
of the pin), and then place a sheave pin support
bar (rectangular plate with threaded holes on
each side of pin bore hole).
e. Slide the whole anchor block/cylinder assembly
with sheave pin, wheels and pin support bars
into top of mast section-2.
f. Align the threaded holes in the attach bars on
each side of the mast and attach to top of mast
section-2 using two (2) 3/8"-16UNC x 1/2" long
socket head-countersunk-flathead cap screws
each side. Coat threads with Loctite #171 and
tighten.
16. Slide mast section-2 back into section-1 until top
and bottom ends are even.
MAST SECTION 3 - ASSEMBLY
IMPORTANT
SPRAY THE SLIDE PAD CHANNELS WITH KRYTOX LUBRICANT AT
ROOM TEMPERATURE (APPROX. 70°) BEFORE ASSEMBLING MAST
SECTIONS TOGETHER AND SHIMMING SLIDE PADS.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
17. Locate the remaining mast section-3 (platform
mounting - mast section). Lay mast section on flat
stable surface.
18. Attach the chain bottom anchor plate (one with
threaded holes aligned at the outside of bracket).
Attach through set of holes in bottom of mast sec-
tion-3 with four (4) 1/4"-20UNC x 3/4" long bolts,
place a flatwasher under head of each bolt.
NOTE: The platform mounting section slide pads, are
assembled differently than the slide pads for the
other mast sections. Mast section-3 slide pads may
need to be assembled/disassembled several times in
order to determine the correct shim stock required
for proper fit.
19. Complete the following steps to determine shim
stock thickness required for section-3;
NOTE: Always use an even amount of shim material behind
slide pads on both sides of the mast rails. This will
keep mast sections centered in rail channels and
prevent any distortion of the section.
a. Use two shim pieces per slide pad, a thick one
and a thin one.
b. Start with a total thickness of approximately
.035" and .075" thick shim stock.
c. Attach shim stock and slide pads to both sides
of mast section-5 using five (5) 1/4"-20UNC x 1-
1/4" long, hex head cap screws per side, with
flatwasher under each bolt head. (Assemble
shim stock and slide pad to mast section rail with
shim stock against rail and slide pad with bev-
eled side out).
d. Carefully thread the slide pad mounting bolts
with flat washers through slide pads and shim
stock into threads in mast section-5. Be certain
there are no air gaps between shims, shim and
mast or shim and slide pad when tightened.
NOTE: Mast section-3 into section-2 fit should be very snug
but still be able to be pushed together by hand. If too
tight, remove section-3, disassemble slide pad and
reduce thickness of shim stock.
Mast Section 2 - Cylinder/Anchor Block
(Sheave Wheel Assembly)
1. Support Bar Screws(a) 4. Sheave Wheel Assy.
2. Pin Support Bars 5. Sheave Pin
3. Narrow Washer 6. Square Keys
Notes: (a) Apply Loctite #242 to threads.
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