Blade Holder Assembly Removal And Installation; Blade Replacement; Slip Clutch Operational Check - Bush Hog 280 Series Operator's Manual

5. PTO Driveline - Disconnect PTO driveline, pull
the two sections apart, apply thin coat of multi-
purpose grease to inside of outer (female) sec
tion. Reassemble sections and install. Pull each
section to be sure driveline and shields are
securely connected. Make certain PTO shielding
is in good condition.
6. Gearbox - Add EP80W-90 gear oil as necessary
to bring oil level to check plug on side of housing.
(4) Before Each Use
(1) Before Each Use
To remove yoke shield, rotate the two fasteners to
allow shield to slide back.
WARNING
THE CUTTER CAN FALL FROM HYDRAULIC
SYSTEM FAILURE. TO AVOID SERIOUS
INJURY OR DEATH, SECURELY SUPPORT
CUTTER BEFORE WORKING UNDERNEATH.
4-3 BLADE HOLDER ASSEMBLY,
REMOVAL AND INSTALLATION
A. Remove cotter pin and blade holder assembly
retaining nut.
B. Wearing heavy gloves, grasp blade holder
and pull off shaft. If stuck, align bolt with access hole
in top of cutter deck. Using hammer and a piece of
pipe, strike blade bar. Rotate pan ato other blade
bolt and strike blade bar. Repeat until blade holder
comes off. Care should be taken not to damage
blade bolt threads.
TO INSTALL:
A. Place blade holder assembly, washer and
retaining nut on lower shaf . Torque nut to 450
ft./lbs. (609.7 Nm) using a 1-1/2" socket.
B. Using a sledge hammer, strike the blade pan
firmly on each end (on or near the head of the blade
bolt) several times, alternating ends between blows.
Retighten to 450 ft./lbs. (609.7 Nm).
C. Install cotter pin. It may be necessary to
tighten nut slightly to install cotter pin.
4-4 BLADE REPLACEMENT (Figure 4-2)
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. Always replace both blades on a spindle using
two blades having the same weight. Use only gen-
uine Bush Hog replacement parts.
A. Raise cutter and securely block in position.
(5) Before Each Use
Figure 4-1 Lubrication
(3) Before Each Use
(2) Before Each Use
Figure 4-2 Blade Nut Removal
B. Remove nuts from blade bolts using a 1-11/16"
socket through the access hole in the deck.
C. Inspect blade bolt shoulder for wear. Replace
if necessary.
D. Assemble new blades to blade holder using
blade bolts, nuts and lockwashers. Tighten nuts to
450 ft./lbs. Strike blade bolt head with heavy ham-
mer to seat, 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, damaging implement.

4-5 SLIP CLUTCH OPERATIONAL CHECK

After implement had been stored for 30 days or
more, perform the following operational check:
A. Loosen eight nuts retaining clutch springs 1/3
turn or until spring can be turned with fingers.
B. With tractor at idle speed, engage tractor PTO
drive for 2-3 seconds. Clutch should slip without
12
(6) Before Each Use
1-11/16" Socket