JLG 4017PS Service Manual - Manual (Page 78)

Boom
3-40 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
3.19 FORKS
Forks should be cleaned and inspected prior to being
attached to carriage. If the following criteria is not met,
forks must be removed from service immediately.
Daily Inspection
1. Inspect forks (8) for cracks, paying special attention
to heel (9) and mounting tubes (10).
2. Inspect forks for broken or bent tips (11) and twisted
blades (12) and shanks (13).
Yearly Inspection
1. Straightness of the upper face of blade (12) and the
front face of shank (13) should not exceed 0.5
percent of the length of blade or height of shank.
2. Angle (14) between upper face of blade and front
face of shank should not exceed 93 degrees.
3. Thickness of blade (15) and shank (16) should not
be reduced to 90 percent of original thickness.
Note: Contact the local JLG dealer with the fork part
number to find the manufactured dimensions of the fork
blade.
4. Ensure fork length (17) is adequate for intended
loads.
5. Fork markings should be legible, re-stamp if
required.
6. Compare fork tips (18) when mounted on a carriage.
Maximum difference in height of fork tips is 3 percent
of the length of the blade (15).
3.20 BOOM PROP (IF EQUIPPED)
3.20.1 Installation and Removal Procedures
a. Prop Installation
1. Park the machine on a firm, level surface. Place the
transmission control lever in (N) NEUTRAL, engage
the park brake switch.
2. Raise the boom to an angle of approximately 20
degrees. Stop engine.
3. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel.
4. Before installing the boom prop, inspect the prop for
damage. Do not use if the prop is damaged or if the
o-rings are damaged or missing.
5. Install the boom prop (1) onto the lift/lower cylinder.
Install o-rings (2). Align lift cylinder lock so the o-
rings are on the bottom side of the lift/lower cylinder
rod.
MH6460
10
13
9
14
12
8
11
16
15
17
18
WARNING
A raised boom can fall if a hydraulic component is
removed. Remove any load, retract the boom and
install the boom prop or a suitable supporting stand
before working under a raised boom.
MAM1280
2
3
2
1