Gradall 544D (9136-4003) Service Manual - Manual (Page 304)

G ENERAL
The four-section boom assembly is raised or lowered by two lift cylinders, fastened to the
main frame and boom-section 1. The lift cylinders are mounted approximately 3 feet from
the back of the boom. The boom assembly pivots on a single base pin that fits into the
main frame and the rear of boom-section 1, at the back of the machine. The pivot pin
turns in bushings pressed into their respective bores. The boom assembly is mechanically
attached to the main frame by the boom pivot pin & bushing (tolerances furnished on
page 9.6).
R EAR: B OOM- S ECTION 1
E XTENDING AND R ETRACTING THE B OOM
The boom is extended and retracted by means of the following components:
A crowd cylinder which has its base pinned to the bottom of boom-section 1 and
the rod end pinned to the bottom of boom-section 2.
Extend chains (1") fastened to the top of their respective booms.
Retract chains fastened to the bottom of their respective booms;
3/4" boom-section 4 to boom-section 2
1" boom-section 3 to boom-section 1.
B
OOM
A
SSEMBLY:
O
VERVIEW
2.0
1.
2.
3.
B OOM- S ECTION 3/2/1 :
S HOWING E XTEND/ R ETRACT C HAINS
Note!
For instructions on removal,
adjustment and installation of
extend and retract chains, see
Sections 4-6
F ORM N O. 29702
l l l l l
544C/544D B OOM M AINTENANCE