Sharpening Or Replacing Chipper Blade - Craftsman 247.770550 Operator's Manual

SHARPENING O RREPLACING C HIPPER
BLADE
Because the engine on this unit has a tapered
crankshaft, a special impeller removal tool (part
number 753-0900) is required to remove the impeller
assembly. For further assistance, contact your Sears
Service Center.
NOTE:
When tipping the unit, empty the fuel tank
and keep engine spark plug side up.
• Disconnect and ground the spark plug wire to
retaing post.
• Remove hose assembly and bag assembly.
• Remove the front hubcaps, flange lock nuts, front
wheels, and wave washers that attach to the pivot
arm assemblies. See Figure 19.
Hubca
Height Adj.
Pivot Arm Assembly
Thrust Washer
Shoulder
Screw Flange Lock Nut
Figure 19
• Remove the shoulder screws, thrust washers,
and bell washers that go through the pivot arms
to the front support brace. The front support
brace and lock nut can be removed at this time as
well.
• Remove the three screws on the upper housing
that secure the nozzle cover and the nine screws
that secure the lower housing to the upper
housing. See Figure 20.
Housing
Nozzle
Screws
Figure 20
Lower Housing
Screws
Remove flange lock nut that secures flail screen
to the lower housing. The flail screen does not
have to be removed. Refer to Figure 17.
Remove the hex bolt, lock washer, and flat
washer that secure the impeller assembly to the
crankshaft. See Figure 21.
o_Upper
_Housing
Impeller
JAssembly
Hex Bolt
Lock Washer
Flat Washer
_Flail
Blade
BOTTOM VIEW
Figure 21
• Apply lubricant to the threads of impeller removal
tool and then thread the tool into the crankshaft.
Stop when the impeller assembly can move on
the crankshaft.
• Remove the impeller assembly from the
crankshaft. Unthread the impeller removal tool
from the impeller assembly.
• Remove the chipper blade using a 3/16" allen
wrench on the outside of the blade and 1/2"
wrench on the underside of impeller assembly.
• Replace or sharpen chipper blade. The blade can
be sharpened with a file or on a grinding wheel.
• When sharpening blade, protect hands by using
gloves and follow the original angle of grind.
• Reassemble by performing the previous steps in
the opposite order and manner of removal.
• Tighten blade screws to 210 - 250 in-lbs.
• Tighten impeller bolt to 375 - 425 in-lbs.
NOTE:
Make certain chipper blade is reassembled
with the sharp edge facing upward. See Figure 22.
Chipper
Flail .... Blade
Blade
Impeller
Assembly
Figure 22
16