JLG 20VP (3120849) Service Manual - Manual (Page 41)

SECTION 2 - SERVICE PROCEDURES
3120849 – JLG Lift – 2-23
2.8 MAST ASSEMBLY AND DISASSEMBLY
PROCEDURES
The VP Series personnel lift mast sections are contructed
of extruded aluminum, protected with an anodized surface
finish. The mast sections are interlocked into each other
when assembled, by internally mounted slide pads at the
top and bottom of each mast section. These slide pads
run up and down in slide pad channels on each side of
the mast.
Each VP model mast assembly contains a different num-
ber of mast sections as shown following;
Assembly procedures for all mast sections is basically the
same, carefully slide the mast sections together from bot-
tom until mast ends are even. (When sliding the mast sec-
tions together, be careful not to scratch the anodized
surface). Assemble the hardware to the bottom of mast
section first, slide this section out the top of previous sec-
tion and assemble hardware to the top of mast, (See Fig-
ure 2-1.). Always install slide pad shims with slide pads
inserted into the slide pad channels, (ends of mast sec-
tions even). Applying silicone spray onto the slide pads
and slide pad channels before assembly will help mast
sections slide easier after slide pads have been properly
shimmed.
Mast Disassembly Procedure
NOTE: Reference to mast sections-3/-4/-5 (platform mount-
ing section) depends on which VP model lift you are
working on.
1. After the mast assembly has been removed from the
machine, lay the mast assembly down on a suitable
work table with the platform mounting section on
top, facing up.
2. Remove the sequencing cables and hardware from
the sides of the mast assembly. Also remove the
cover from the top of the mast assembly.
3. Remove chain adjust nuts from threaded ends of
chain attached to the chain anchor plate on BOT-
TOM end of mast section-3/-4/-5 (platform mounting
section). Push threaded ends of chain through
anchor plate.
4. At the TOP of mast section—3/-4/-5, pull chains out
and allow to hang loose.
Table 2-2. VP Series Mast Component Features
Model
No. of Mast
Sections
Extend/Retract
Device
10VP 3 Chain
15VP 4 Chain
20VP 5 Chain
Figure 2-16. Mast Section - Assembly Reference.
OPEN RAIL
(REFERS TO OPEN RAIL
FRONT OF MAST SECTION)
CLOSED RAIL
(REFERS TO CLOSED RAIL
BACK OF MAST SECTION)
BOTTOM
(REFERS TO BOTTOM END OF
MAST SECTION WHICH SETS IN
MACHINE’S BASE FRAME)
TOP
(REFERS TO TOP END
OF MAST SECTION
WHERE COVER AND
SHEAVE WHEELS
ARE ATTACHED)