JLG 19BD Service Manual - Manual (Page 55)

SECTION 2 - SERVICE PROCEDURES
3121154 – JLG Lift – 2-33
Mast To Base Frame Installation
1. Using an overhead crane or suitable lifting device
capable of supporting the weight of mast assembly,
attach a sling strap around the mast assembly at the
AC Junction Box/Ground Control Station support
bracket.
NOTE: When lowering mast assembly into the base frame
carefully guide the manual descent valve assembly
into the recess at the rear of the base frame to avoid
damage to the valve.
2. Carefully lift the mast assembly and lower into the
base frame until the four (4) mounting holes on bot-
tom rear of mast align with holes in the base frame
mast support at the rear of the base frame.
3. Attach mast to base using four (4) 3/8"-16UNC x 1"
long hex head bolts, locknuts and flatwashers,
(place a flatwasher under bolt head (on outside of
frame) and under the nut, mount with nuts on the
inside of base frame on mast rail).
4. Swing the two (2) mast support braces up attached
to sides of base frame support brackets.
NOTE: Do not completely tighten the mast side support
bracket bolts until mast is checked for vertical align-
ment (plumb).
5. Attach support braces to the mast support bracket,
(bolted to mast), using 3/8"-16UNC x 2-3/4" long hex
head bolts, nuts and flatwashers. (Place a flatwasher
under bolt head and nut and mount with nuts on
inside of bracket).
6. Using a 4 ft. level, ensure mast is set to vertical
(plumb) on the base frame.
7. When mast is vertical (plumb), secure mast side
supports to base frame bracket and mast support
bracket. Using 4 ft. level again check that mast is
vertical (plumb) on base frame. If not vertical loosen
side brace bolts slightly, plumb mast, retighten side
brace bolts.
8. Reattach platform assembly.
9. Run mast assembly up and down a few times check-
ing chain and sequence cable adjustment.
Mast installation should now be complete.