JLG 41AM (3120872) Service Manual - Manual (Page 51)

SECTION 2 - SERVICE PROCEDURES
3120872 – JLG Lift – 2-29
45. Shim per instructions in step 7, Mast Section 2 -
Assembly.
Mast Section 5 - Assembly
(25/30/36/41 ft. Masts)
NOTE: Steps 43 thru 56 apply to six (6) section 25 and 36 ft.
and seven (7) section 30 and 41 ft. masts only. For
five (5) section 20 ft. masts continue to step 70.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
46. Locate mast section-5, carefully slide section-5
closed rail into section-4 open rail. Slide sections
together until ends are even.
47. Locate one (1) of the chain anchor plates (one with
threaded holes horizontally aligned to outside edges
of bracket). Attach through outer set of holes in bot-
tom of mast section-5 with two (2) 1/4"-20UNC x 3/4"
long bolts, place a flatwasher under head of each
bolt.
NOTE: Step 48 applies to seven (7) section 30 and 41 ft.
masts only for six (6) section 25 and 36 ft. masts
continue to step 49.
48. Slide mast section-5 out the top of mast section-4 so
the chain anchor plate on bottom of mast section-5
is easily accessible near top end of mast section-4.
Rest the top end of mast section-5 on a support
while performing next step.
49. Insert threaded ends of chain assembly (attached to
top of mast section-3) through the chain anchor
plate located on bottom of extended mast section-5.
Loosely thread two (2) 3/8"-16UNC nuts onto stud
threads on each chain. Chains will be adjusted later
in assembly.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
50. Slide mast section-5 back into section-4 except for a
foot or two of length.
51. Locate two chain assemblies. Attach the eyelet
anchor end of each chain to the two inside holes
near top of mast section-5 using 3/8"-16UNC x 1-1/4"
long hex head bolts, nuts and flatwashers. Place a
flatwasher under bolt head and nut.
52. While mast section-5 is still extended from section-4,
assemble chain sheaves to top of mast section-5 as
follows;
a. Locate remaining sheave pin. Slide two (2) chain
sheave wheels onto sheave pin and center.
b. Place two (2) short spacer tubes on sheave pin,
one on each end of sheave pin to outside of
sheave wheels.
c. Place two (2) sheave pin attach bars, one on
each end of sheave pin to outside of short
spacer tubes.
d. Holding complete chain sheave wheel assem-
bly, slide assembly into top of mast section-5
and align threaded holes in sheave pin attach
bars with holes in mast rails.
e. Attach to top of mast section-5 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.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
53. Carefully slide mast section-5 back into section-4
until ends are even. Check to make sure chain set
from top of section-3 is seating properly in chain
sheave wheels attached to top of mast section-4.
(Mast sections-2, -3 and -4 may need to be
restrained to keep their slide pads from pushing out
the bottom of mast sections-1, -2 and -3).
54. Insert slide pads into the top end mast rails between
section-4 and -5, (one on each side of the mast),
with beveled surface facing inward towards section-
5.
NOTE: Before fastening and shimming the slide pad on the
top left side of the mast, install a sequence cable
bracket against the mast under the flatwasher.
55. 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 in
outside rail, on top of mast section-4 and into the
slide pad inserts. Thread in enough to hold pad in
place.
56. Shim per instructions in step 7, Mast Section 2 -
Assembly.
57. Insert slide pads into the bottom end mast rails
between section-4 and -5, (one on each side of the
mast), with beveled surface facing out towards sec-
tion-4.
58. 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-4 and into
the slide pad inserts. Thread in enough to hold pad
in place.
59. Shim per instructions in step 7, Mast Section 2 -
Assembly.