Toro 74312 Operator's Manual page 57

Sharpening the Blades
1. Use a file to sharpen the cutting edge at both
ends of the blade
Note:
Maintain the original angle.
Note:
The blade retains its balance if the same
amount of material is removed from both cutting
edges.
Figure 65
1. Sharpen at original angle.
2. Check the balance of the blade by putting it on a
blade balancer (Figure
Note:
If the blade stays in a horizontal position,
the blade is balanced and can be used.
Note:
If the blade is not balanced, file some
metal off the end of the sail area only
Figure 66
1. Blade
3. Repeat this procedure until the blade is
balanced.
(Figure 65).
66).
(Figure
2. Balancer
Installing the Blades
Note:
Determine the left and right sides of the
machine from the normal operating position.
Note:
Ensure that you install the red-colored blade
on the right side.
1. Install the blade driver to the new blades with
the shear bolts and locknuts
2. Torque the shear bolts to 922 to 1130 N∙m (80
to 100 in-lb).
Note:
Align the blade-driver flats with the flats
on the shaft when installing the blade on the
mower deck.
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3. Install the blade, washer, and blade bolt to the
spindle shaft
4. Torque the blade bolt to 115 to 149 N∙m (85 to
110 ft-lb).
5. Lower the mower deck to the operating position.
Refer to Lowering the Mower Deck to the
Operating Position (page
WARNING
65).
Operating a mower deck with loose or
weakened blade bolts can be dangerous.
A loose or weakened blade bolt could
allow a blade rotating at a high speed
to come out from under the mower
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deck, causing serious injury or property
damage.
• Replace the blade bolt after striking a
foreign object.
• Use only genuine Toro replacement
parts.
• Do not lubricate the threads of the
bolt or spindle before assembly.
57
(Figure
(Figure 64).
18).
64).