JLG 19AMI (3120758) Service Manual - Manual (Page 43)

SECTION 2 - SERVICE PROCEDURES
3120758 – JLG Lift – 2-29
outside rail, on top of mast section-2 and into the
slide pad inserts. Thread in enough to hold pad in
place.
31. Shim per instructions in step 7, Mast Section 2 -
Assembly.
32. Insert slide pads into the bottom end mast rails
between section-2 and -3, (one on each side of the
mast), with beveled surface facing out towards sec-
tion-2.
33. Thread slide pad attaching bolts, two (2) 1/4"-
20UNC x 3/8" long hex head bolts, place a flat
washer under head of each bolt, through holes on
inside rail, on bottom end of mast section-3 and into
the slide pad inserts. Thread in enough to hold pad
in place.
34. Shim per instructions in step 7, Mast Section 2 -
Assembly.
Platform Mounting Section - Assembly
35. Locate the remaing mast section-4 (platform mount-
ing - mast section). Lay mast section on flat stable
surface.
36. Attach the remaining chain/cable anchor plate (one
with threaded holes vertically aligned in center of
bracket). Attach through inner (vertical) set of holes
in bottom of mast section-5/-6/-7 with two (2) 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 slide pads may
need to be assembled/disassembled several times in
order to determine the correct shim stock required
for proper fit.
37. Complete the following steps to determine shim
stock thickness required for section-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-4. Be certain
there are no air gaps between shims, shim and
mast or shim and slide pad when tightened.
NOTE: Mast section-4 into section-3 fit should be very snug
but still be able to be pushed together by hand. If too
tight, remove section-4, disassemble slide pad and
reduce thickness of shim stock.
e. Begin sliding top of mast section-4 with closed
rail down engaging the slide pads into slide pad
channels at bottom of mast section-3’s open rail.
Continue to push section-4 into section-3 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.
38. Slide mast section-4 out to top of section-3.
39. Insert threaded ends of cable assembly (attached to
top of mast section-2) through the cable anchor
plate located on bottom of extended mast section-4.
Loosely thread two (2) 3/8"-16UNC nuts onto stud
threads on each chain. Chains will be adjusted later
in assembly.
40. Slide mast section-4 back into mast section-3 until
bottom ends of masts are even. Check to make sure
cable set attached to top of section-2 is seating
properly in cable sheave wheels attached to top of
mast section-3. (Mast section-2 may need to be
restrained to keep it’s slide pads from pushing out
the bottom of mast sections-1).
41. Adjust top and bottom ends of mast sections so they
are all even with each other. At bottom of mast
assembly, thread all chain/cable adjusting nuts on
threaded ends until they are snug against the
anchor plates and all slack is removed from chains
and cables. Check that chains and cables are
seated in their sheave wheels at top of mast assem-
bly.
42. 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.