National Crane 600H, Service Manual

Page: 204 / 232

CRANE INSTALLATION 600H SERVICE
9-22
08-19-2022 Control # 092-13
frame, cut out plug weld hole pattern as in Figure B.
Slide the reinforcing angle up from the bottom, butt it to
existing forward reinforcing and weld rear suspension
reinforcing to forward reinforcing. Replace as much of
the spring hanger cut out areas as possible and butt
weld these pieces in.
If reinforcing angle is to be bolted on, drill hole pattern and
install bolts according to Figure C. Reinforce spring hanger
cut outs and the weld area, suspension reinforcing to forward
reinforcing by adding bars under these areas. The bars
should be of the same thickness, width and yield strength as
the reinforcing angle lip, and should be long enough to
extend at least 6 in (152 mm) beyond either side of the weld
or cut out areas. Weld these reinforcing bars to the underside
of the reinforcing with length-wise welds. Do Not Weld
Across The Flanges. Replace any equipment that had been
removed.
AFTER FRAME MODIFICATION
If additional suspension reinforcing is required, as may be
t h e c a s e w i t h a t r u c k f r a m e t h a t t a p e r s d o w n t o
approximately 6 in (15.24 cm) deep through the suspension,
a channel may be fabricated through the suspension for
additional strength. To do this, install the angle as described
in the previous step, making sure that the long leg of the
angle extends to the top of the truck frame. A bar of the same
material strength, thickness, length and flange width as the
reinforcing angle is then added to the top of the truck frame.
The bar is butt welded to the top of the forward reinforcing,
then skip-welded with 6 in (15.24 cm) of weld, 6 in (15.24 cm)
no weld, etc., along both edges of the bar, front to back.
Length of after frame (AF) may have to be modified for crane
installation. If AF is too long, cut off excess and remove any
Weld 6 (152)
Skip 6 (152)
Weld 6 (152)
Skip 6 (152)
Weld 12 (304)
Reinforcing under crane
Cut outs Replace as much
material as possible. Butt weld
Overload spring stop.
Remove and replace.
S
kip
w
eld
a
ll b
ars
w
ith
a
lte
rn
ate
w
eld
alo
ng
b
oth
e
dg
es
Truck frame (REF)
Reinforcing (REF)
6 (152)
6 (152)
6 (152)
6 (152)
Butt weld
NOTE: All dimensions are
in (mm)
Figure D
REFERENCE ONLY