JLG 20VP (3120728) Service Manual - Manual (Page 51)

SECTION 2 - SERVICE PROCEDURES
3120728 – JLG Lift – 2-33
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/cable 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/cable anchor plate on bottom of mast sec-
tion-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 cable/chain assembly
(attached to anchor block on top mast section-2)
through the chain/cable anchor plate located on bot-
tom 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
cables/chains to mount sheave wheels to top of
mast section-3.
34. Extend mast section-3 out far enough from section-2
mast to gain access to top of section-3.
35. Assemble cable/chain sheaves to top of mast sec-
tion-3 as follows;
a. Locate the two cable/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 cable assemblies. Attach the eyelet
anchor end of each cable 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 cable sheaves to top of mast section-4 as
follows;
a. Locate the wide tube spacer and slide onto
sheave pin.
b. Slide two (2) cable 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 cable sheave wheels.
d. Place two (2) sheave pin attach bars, one each
end of sheave pin to outside of large flatwash-
ers.