JLG 20VP (3120849) Service Manual - Manual (Page 48)

SECTION 2 - SERVICE PROCEDURES
2-30 – JLG Lift – 3120849
this manner, due to the tight fit of the slide pads in
the slide pad channels, the anodized finish could be
removed from the receiving mast’s slide pad chan-
nels.
23. Insert slide pads into the top end mast rails between
section-2 and -3, (one on each side of the mast),
with beveled surface facing inward towards section-
3.
24. 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-2 and into the
slide pad inserts. Thread in enough to hold pad in
place.
25. Shim per instructions in step 7.
26. 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.
27. 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.
28. Shim per instructions in step 7.
NOTE: Assembly of 10VP mast should now be complete. To
continue with 15VP assembly go to step 48. 20VP
assembly continues following.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
29. Locate mast section-4, carefully slide section-4
closed rail into section-3 open rail. Slide sections
together until ends are even.
30. Locate one (1) of the chain anchor plates (one with
two threaded holes vertically aligned in center of
bracket). Attach through inner (vertical) set of holes
at bottom of mast section-4 using two (2) 1/4"-
20UNC x 3/4" long bolts, place a flatwashers under
head of each bolt.
31. Slide mast section-4 out the top of mast section-3 so
the chain anchor plate on bottom of mast section-4
is easily accessible at top end of mast section-3.
Rest the top end of mast section-4 on a support
while performing next step.
32. Insert threaded ends of chain assembly (attached to
anchor block on top mast section-2) through the
chain 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.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
33. Slide mast section-4 back into mast section-3 except
for about a foot or more. Allow enough slack in
chains to mount sheave wheels to top of mast sec-
tion-3.
34. Extend mast section-3 out far enough from section-2
mast to gain access to top of section-3.
35. Assemble chain sheaves to top of mast section-3 as
follows;
a. Locate the two chain sheave wheels and slide
onto sheave pin.
b. Slide two (2) short spacer tubes onto sheave
pin, one each end of sheave pin to outside of
sheave wheels.
c. Place two (2) sheave pin attach bars, one each
end of sheave pin to outside of space tubes.
d. Holding complete sheave wheel assembly, slide
assembly into top of mast section-3 and align
threaded holes in sheave pin attach bars with
holes in mast rails.
e. Attach to top of mast section-3 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.
36. Slide mast section-3 back into section-2 until ends
are even. (Mast section-2 may need to be restrained
to keep its slide pads from pushing out the bottom
of mast section-1).
37. While mast section-4 is still extended from section-3;
locate two chain assemblies. Attach the eyelet
anchor end of each chain to the inside set of holes
near top of mast section-4 using 3/8"-16UNC x 1-1/4"
long hex head bolts, nuts and flatwashers. Place a
flatwasher under bolt head and nut.
38. While mast section-4 is still extended from section-3,
assemble chain sheaves to top of mast section-4 as
follows;
a. Locate the wide tube spacer and slide onto
sheave pin.
b. Slide two (2) chain sheave wheels onto sheave
pin, one each end of sheave pin to outside of
tube spacer.
c. Place two (2) large flat washers, one each end of
sheave pin to outside of chain sheave wheels.
d. Place two (2) sheave pin attach bars, one each
end of sheave pin to outside of large flatwash-
ers.