JLG 20VP (3120728) Service Manual - Manual (Page 50)

SECTION 2 - SERVICE PROCEDURES
2-32 – JLG Lift – 3120728
bracket). Attach using outer set of holes in bot-
tom of mast section-3 with two (2) 1/4"-20UNC x
3/4" long bolts, place a flatwasher under head of
each bolt.
14. Slide mast section-3, approximately two feet out of
the top of mast section-2.
15. Insert threaded ends of cable/chain-assembly #466
(attached to top of mast section-1), through holes in
anchor plate attached to bottom of mast section-3.
Loosely thread two (2) 3/8"-16UNC nuts onto stud
threads on each chain. Cables/chains will be
adjusted later in assembly.
16. Slide mast section-2 out of mast section-1 approxi-
mately one foot.
10VP Top of Cylinder Assembly
19. Assemble cable sheave wheels to cylinder rod end
and attach to mast section-2 using following steps;
a. Attach cable mounting tube to top of hydraulic
cylinder using one (1) 1/4"-28NF x 5/8" cap-
screw.
b. Insert sheave pin through cylinder cable mount-
ing tube on cylinder rod end.
c. Place a spacer tube on each side of mounting
tube.
d. Next slide sheave wheels on onto sheave pin
against spacer, on each side of mounting tube.
e. On outside of each sheave wheel, place another
spacer tube.
f. On outside of spacer tubes place a sheave pin
attach bar, (rectangular plate with threaded holes
on each side of pin bore hole).
g. Slide the assembly with sheave pin, wheels and
pin attach bars into top of mast section-2.
h. Attach to top of mast section-2 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.
15VP Top of Cylinder Assembly
19. Assemble cable sheave wheels to cylinder rod end
and attach to mast section-2 using following steps;
a. Attach cable mounting tube to top of hydraulic
cylinder using one (1) 1/4"-28NF x 5/8" cap-
screw.
b. Insert sheave pin through cylinder cable mount-
ing tube on cylinder rod end.
c. Place a spacer tube on each side of mounting
tube.
d. Next slide sheave wheels on onto sheave pin
against spacer, on each side of mounting tube.
e. On outside of each sheave wheel, place another
spacer tube.
f. On outside of spacer tubes place a sheave pin
attach bar, (rectangular plate with threaded holes
on each side of pin bore hole).
g. Before sliding this assembly into the top of mast
section two, locate two (2) mast extension cable
assemblies and lay their anchor ends into the
slots of the cable mounting tube.
h. Slide the assembly with sheave pin, wheels and
pin attach bars into top of mast section-2.
i. Attach to top of mast section-2 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.
20VP Top of Cylinder Assembly
19. Assemble chain sheaves on chain assembly #444
anchor block (attached to cylinder rod end) and
attach to mast section-2 using following steps;
a. Insert sheave pin through anchor block on cylin-
der rod end.
b. Place sheave wheels (for wide chain) on sheave
pin, one each side of anchor block.
c. On outside of each sheave wheel, place a
sheave pin attach bar, (rectangular plate with
threaded holes on each side of pin bore hole).
d. Slide the whole anchor block assembly with
sheave pin, wheels and pin attach bars into top
of mast section-2. (Position anchor block with
narrow chains facing mast section-3).
e. Attach to top of mast section-2 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.
20. Slide mast section-2 back into section-1 until end
are even.
NOTE: Step 23 and 24 applies to 20VP mast assembly only.
10VP and 15VP mast assembly continue at step 25.
21. Locate two mast extension cable assemblies. Attach
the eyelet anchor end of each cable to the outside
holes near top of mast section-3 using 3/8"-16UNC x
1-1/4" long hex head bolts, nuts and flatwashers.
Place a flatwasher under bolt head and nut.
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
22. Carefully slide mast section-3 into section-2 until
ends are even. Check to make sure chain assembly
#466 (wide chains) are seating properly in chain
#444 anchor block chain sheave wheels attached to
mast section-2.
NOTE: Do not attach mast slide pads and shims to mast
sections before assembling sections. If assembled in