JLG 15SP Service Manual - Manual (Page 43)

SECTION 2 - SERVICE PROCEDURES
3120775 – JLG Lift – 2-29
46. Shim per instructions in step 7, Mast Section 2 -
Assembly.
Platform Mounting Section - Assembly
47. Locate the remaing mast section-4/5 (platform
mounting - mast section). Lay mast section on flat
stable surface.
48. Attach the remaining chain bottom anchor plate
(one with threaded holes aligned at the outside of
bracket). Attach through set of holes in bottom of
mast section-4/5 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-4/5 slide pads
may need to be assembled/disassembled several
times in order to determine the correct shim stock
required for proper fit.
49. Complete the following steps to determine shim
stock thickness required for section-3/4;
NOTE: Always use the an even amount of shim material
behind slide pads on both sides of the mast rails.
This will keep mast sections centered in rail chan-
nels 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/-6/-7 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 flatwashers 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-4/5 into section-3/4 fit should be very
snug but still be able to be pushed together by hand.
If too tight, remove section-4/5, disassemble slide
pad and reduce thickness of shim stock.
e. Begin sliding top of mast section-4/5 with closed
rail down engaging the slide pads into slide pad
channels at bottom of mast section-3/4’s open
rail. Continue to push section-4/5 into section-3/
4 until BOTTOM ends of mast sections are even.
f. Check mast section for side play. If play exists
use thicker shims dividing thickness equally
between both sides of mast.
g. When mast slide pads are shimmed properly,
there should be no side to side movement of
slide pad in rail channel. Mast sections should
be very snug in channels but still be able to slide
in channel by hand.
50. Slide mast section-4/5 out even with top of section-
3/4.
51. Insert threaded ends of chain assembly (attached to
top of mast section-2/3) into the opening between
mast section-3/4 and mast section-4/5. Slide the
threaded ends through the holes in bottom chain
anchor plate located on bottom of mast section-4/5.
Loosely thread two (2) 3/8"-16UNC nuts onto stud
threads on each chain. Chains will be adjusted later
in assembly.
52. Slide mast section-4/5 back into mast section-3/4
until bottom ends of masts are even. Check to make
sure chain set attached to top of section-2/3 is seat-
ing properly in cable sheave wheels attached to top
of mast section-3/4. (Mast section-2/3 may need to
be restrained to keep it’s slide pads from pushing out
the bottom of mast sections-1/2).
53. Adjust top and bottom ends of mast sections so they
are all even with each other. At bottom of mast
assembly, thread all chain adjusting nuts on
threaded ends until they are snug against the bot-
tom anchor plates and all slack is removed from
chains. Check that chains are seated in their sheave
wheels at top of mast assembly.
54. Assemble the mini covers to the top of each mast
section and the sequencing cables and hardware to
the side of the mast assembly.
Mast assembly should now be complete.
2.10 MAST TO BASE FRAME INSTALLATION
1. Using an overhead crane or suitable lifting device
capable of supporting the weight of base frame,
attach a sling strap or chain to the front crossmem-
ber of the base frame, raise base frame.
2. Extend hydraulic cylinder out from bottom of mast
assembly approximately one (1) foot. (Caps on
extend and return ports will need to be removed to
extend cylinder. Catch any hydraulic fluid expelled
from return port in a container to prevent spillage
onto work area).
3. Bring base frame into position in front of mast
assembly, (base frame and mast assembly must be
held at 90° angle to each other).