JLG 19AMI (3120758) Service Manual - Manual (Page 39)

SECTION 2 - SERVICE PROCEDURES
3120758 – JLG Lift – 2-25
ft. lbs. Align the hole in the mounting journal with the
hole in the cylinder and Install the (1) 5/16" bolt.
16. New Design Cylinder: Install the mounting pin
through the side mounting brackets and the cylinder
valve body and through the mounting brackets on
the other side of the mast. Install the snap rings to
each end of the mounting pin.
17. Insert hydraulic cylinder rod end into chain assem-
bly anchor block. Secure cylinder rod to anchor
block with a 1/4"-28UNF x .50" long - Type C set-
screw. Coat threads with blue Loctite # 242 before
assembly.
18. Locate chain assembly (single anchor block with
two narrow chains). Lay out chain assembly with
anchor block end towards mast, (be certain floor
surface is clean and free of any metal chip or debris
which may stick to lubricated chains or lay chains in
a clean bucket).
19. Slide mast section-2 out of mast section-1 approxi-
mately one foot.
20. Assemble chain sheaves on chain assembly 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.
21. Slide mast section-2 back into section-1 until end
are even.
Mast Section 3 - Assembly
NOTE: When sliding mast sections together, be careful not
to scratch or score the anodized finish in the slide
pad channels.
22. Locate mast section-3, carefully slide section-3
closed rail into section-2 open rail. Slide sections
together until ends are even.
23. Locate one (1) of the chain/cable anchor plates (one
with threaded holes horizontally aligned to outside of
bracket). Attach using outer set of holes in bottom of
mast section-3 with two (2) 1/4"-20UNC x 3/4" long
bolts, place a flatwasher under head of each bolt.
24. Slide mast section-3, approximately two feet out of
the top of mast section-2.
25. Insert threaded ends of chain assembly (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. Chains will be adjusted later in assem-
bly.
26. Locate two 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 flat-
washer under bolt head and nut.
27. Assemble chain sheaves (for narrow chain assem-
bly) to top of mast section-3 as follows;
a. Locate the two (2) narrow 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.
28. Carefully slide mast section-3 into section-2 until
ends are even. Check to make sure chain assembly
(wide chains) are seating properly in chain anchor
block chain sheave wheels attached to mast sec-
tion-2.
29. 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.
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.
30. 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