13
Figure 4-3 Shear Bolt Blade Bolt
A. Raise cutter and SECURELY BLOCK IN
POSITION.
B. Remove nuts from blade bolts using a 1-5/16”
socket. Remove blades, bolts and washers.
C. Inspect blade bolt shoulder for wear. Replace
if necessary. When replacing blade bolt always
replace both bolts.
D.Assemble new blades to blade holder using
blade bolts, nuts and lockwashers. Tighten nuts to
420 ft./lbs. (569 Nm) It may be necessary to hold
blade bolt with pipe wrench. Strike head of bolt sev-
eral times with a hammer, then retighten.
E. Check to be sure blades swing 360° freely. If
blades will not swing freely, remove, locate problem,
and repair. Operating cutter when blades will not
swing freely will cause excessive vibration, damag-
ing implement.
4-4 SHEAR BOLT REPLACEMENT
A. Refer to Figure 4 and slide yoke shield back.
B. Remove sheared bolt from input shaft using
hammer and punch.
C. Inspect retaining clip to make certain it is
securely installed in groove.
4-3 BLADE REPLACEMENT
It is not necessary to remove the complete blade
holder assembly to replace the blades. Blade bolts
are accessible through a hole in the top of the cutter
deck. To maintain proper balance always replace
both blades on a blade holder using two blades hav-
ing the same weight. Use only genuine Bush Hog
replacement blades. (Figure 4-3)
WARNING
DO NOT GET UNDER CUTTER UNLESS IT
IS SECURELY BLOCKED IN POSITION.
ACCIDENTAL FALL COULD CAUSE SERI-
OUS INJURY OR DEATH.
WARNING
FAILURE TO USE CORRECT SIZE SHEAR
BOLT MAY CAUSE PERSONAL INJURY OR
DEATH.
WARNING
FAILURE TO INSTALL RETAINING CLIP
WILL ALLOW DRIVELINE TO SWING
FREELY IF BOLT IS SHEARED CAUSING
POSSIBLE INJURY OR DEATH.
D. Install new 1/2 x 3” Grade 2 shear bolt and lock-
nut. Refer to torque chart on page 15. Higher grade
shear bolt can cause damage to driveline or gearbox.
E. Lock yoke shield securely into place.
4-5 BLADE HOLDER & GEARBOX
REMOVAL
A. Raise cutter using tractor 3-point lift. Turn off
tractor engine.
B. BLOCK CUTTER SECURELY INTO POSITION.
C. Remove cotter pin and blade holder retaining
nut. Wear heavy work gloves to protect hands from
sharp edges.
D. Grasp blade holder and pull off shaft. If neces-
sary, align blade bar with access hole in top of deck
and drive off with hammer and pipe. Care should be
taken not to damage threads on blade bolt.
E. Press all three tabs and slide yoke shield back.
(Figure 4-2)
F. Remove shear bolt and retaining clip. Slide yoke
off gearbox input shaft. (Figure 4-3)
G. Remove nuts securing gearbox to deck.
Remove gearbox.
4-6 BLADE HOLDER AND GEARBOX
INSTALLATION
A. Raise cutter using tractor 3-point lift. Turn off
tractor engine.
B. BLOCK CUTTER SECURELY INTO POSITION.
C. Attach gearbox to cutter deck using bolts and
flange nuts.
D. Install blade holder onto gearbox securing with
castellated nut and flat washer. Torque nut to 350
ft./lbs. (475 Nm). Wear heavy work gloves to protect
hands from sharp edges.
WARNING
DO NOT GET UNDER CUTTER UNLESS IT
IS SECURELY BLOCKED IN POSITION.
ACCIDENTAL FALL COULD CAUSE SERI-
OUS INJURY OR DEATH.
WARNING
DO NOT GET UNDER CUTTER UNLESS IT IS
SECURELY BLOCKED IN POSITION. ACCI-
DENTAL FALL COULD CAUSE SERIOUS
INJURY OR DEATH.
