JLG 120HX ANSI Service Manual - Manual (Page 40)

SECTION 2 - PROCEDURES
2-20 – JLG Lift – 3120686
18. Carefully lift inner mid, outer mid and fly sections
clear of base section and lower to a suitably sup-
ported work area.
19. Using suitable lifting equipment, support telescope
cylinder rod.
20. Remove setscrew securing trunnion pins that secure
inner mid section to telescope cylinder.
21. Using a suitable tool, scribe a line on the outer end
of each trunnion pin and boom structure as an aid to
pin alignment during boom assembly.
22. Using a suitable slide hammer, remove trunnion pins
attaching telescope cylinder to inner mid section.
23. Remove cotter pins and chain attach pins attaching
outer mid section retract chains to lower aft end of
outer mid section and remove chains.
24. Remove setscrews which attach chain sheave pins
at lower aft end of inner mid section.
25. Using a suitable brass drift, carefully drive sheave
pins from inner mid section and remove sheaves
and thrust washers. If necessary, remove bushings
from sheaves and replace. Ensure that pins, grease
fittings and corresponding boom and sheave sur-
faces are not damaged.
26. Remove cotter pins and chain attach pins attaching
fly section retract chains to lower aft end of fly sec-
tion and remove chains.
27. Remove setscrews which attach chain sheave pins
at lower aft end of outer mid section.
28. Using a suitable brass drift, carefully drive sheave
pins from outer mid section and remove sheaves,
seals, and thrustwashers. If necessary, remove
bushings from sheaves and replace. Ensure that
pins, grease fittings and corresponding boom and
sheave surfaces are not damaged.
29. Pull boom sections out several feet to allow ample
clearance for telescope cylinder removal.
30. Remove outer mid section extension chain adjust
nut and locknut from clevis at lower aft end of outer
mid section.
31. Using suitable lifting equipment, carefully slide tele-
scope cylinder out of fly, outer mid, and inner mid
sections, along with extension chain and bar.
32. When approximately one-half of the telescope cylin-
der is removed from the boom assembly, the exten-
sion bar attach to chain will become accessible.
Remove cotter pins and clevis pin attaching exten-
sion bar to chain and remove bar.
33. Carefully lift telescope cylinder clear of boom
assembly and lower to ground or suitably supported
work area.
34. Remove bolts attaching outer mid section retract
chain adjust block at lower front end of inner mid
section and remove block.
NOTE: Note and record number and thickness of any wear
pad shims during wear pad removal.
35. Remove bolts and lockwashers which attach upper
aft inner mid section wear pads and remove pads
and any shims.
36. Remove bolts, washers and lockwashers which
attach bottom wear pads at front of inner mid sec-
tion and remove pads and any shims.
37. Remove bolts and lockwashers which attach side
wear pads at front of inner mid section and remove
pads and any shims.
38. Remove bolts and lockwashers which attach top
wear pad at front of inner mid section and remove
pad and any shims.
39. Using suitable lifting equipment, carefully slide outer
mid and fly sections clear of inner mid section and
lower to ground or other suitably supported work
area.
40. Remove bolts and lockwashers which attach upper
aft outer mid section wear pads and remove pads
and any shims.
41. Remove bolts and lockwashers which attach bottom
wear pads at front of outer mid section and remove
pads and any shims.
42. Remove bolts and lockwashers which attach side
wear pads at front of outer mid section and remove
pads and any shims.
43. Remove bolts and lockwashers which attach top
wear pads to front of outer mid section and remove
pads and any shims.
44. Remove bolt, washer and lockwasher attaching fly
section right hand extend chain sheave attach pin to
front of outer mid section.
45. Using a suitable brass drift, carefully drive each
sheave pin from the boom section and remove the
sheave assemblies. Inspect pins, lubrication fittings
and sheave bearings for damage and dirt or foreign
material. Replace components as necessary.
46. Repeat steps (42) and (43) for left hand sheave.
47. Using suitable lifting equipment, carefully slide fly
section clear of outer mid section and lower to
ground or suitably supported work area.