JLG 534D-10 - Manual (Page 66)

Boom
3.38 534D-9, 534D-10 & 544D
3.13 BOOM SECTION SEPARATION
ADJUSTMENT - FOUR SECTION
The second, third and fourth boom sections are set to
dimensions between each section. The first and second
boom sections are connected by the extend/retract
cylinder which has no adjustment.
The third and fourth boom sections can be adjusted by
loosening or tightening the extend chains and the retract
chains.
a. To increase the separation distance: Loosen the
retract chains locknut on the rear of the third or fourth
boom sections one or two turns and tighten the
extend chain locknuts on the first and second boom
sections equally the same number of turns. A
minimum of one full thread on the clevis must
protrude beyond the locknut.
b. To decrease the separation distance: Loosen the
extend chain locknuts at the front of the first or
second boom sections equally one or two turns and
tighten the retract chains locknut the same number
of turns. A minimum of one full thread on the clevis
must protrude beyond the locknut.
See Section 3.11.7, 3.12. “Boom Extend and Retract
Chains - Four Section.”
Note: If the second boom section to the third boom
section separation distance cannot be achieved, contact
the local JLG distributor or the JLG Service Department.
3.14 HYDRAULIC SUB-ASSEMBLY
REMOVAL/INSTALLATION -
FOUR SECTION
The hydraulic sub-assembly locates primarily in the
fourth boom section. It is fastened at the bottom front of
the fourth boom section and at the rear of the third boom
section.
3.14.1 Hydraulic Sub-Assembly Removal
1. Remove any attachment from the quick switch
assembly. Refer to Section 3.16.1, “Disconnecting
from an Attachment.”
Note: Allow adequate room in front of the machine
when removing and installing the hydraulic sub-
assembly.
2. Park the machine on a hard, level surface, level the
machine, fully retract the boom, level the boom,
place the transmission control lever in (N)
NEUTRAL, engage the park brake and shut the
engine OFF.
3. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
4. Open the engine cover. Allow the system fluids to
cool.
5. Remove the battery negative (-) cable from the
battery negative (-) terminal.
6. Loosen and remove both compression springs (1)
from the hose take-up weldment at the bottom of the
first boom section.
7. Label and disconnect the tilt and auxiliary hydraulic
hoses attached to the sub-assembly at the rear of
the boom and at the front of the boom head. Plug
and cap the hose ends to prevent dirt and debris
from entering the hydraulic system.
8. If equipped, label and disconnect any electrical
connections at the front and rear of the boom
assembly.
Note: Tag or identify each hose to the corresponding
fitting it was removed from.
9. Loosen and remove both cap screws and locknuts
(2) from the sub-assembly bracket at the front of the
fourth boom section.
10. Loosen and remove the guide bracket (3) from the
front of the fourth boom section.
MY2690
1
MY2710
1
3
2