Gravely 990018, 990020 Owner's/Operator's Manual page 17

7. Add new oil to the oil tank. It will take about 4
quarts. Use Mobil 15W50 synthetic oil for best
pump and wheel motor life.
8. Properly dispose of waste oil.
MOWER BLADES
Remove
CAUTION: Use sturdy gloves or padding to
protect hands when working with mower
blades.
1. Turn the engine off. Remove the ignition key.
Remove the ignition wire from the spark plugs.
2. Remove the bolts, lock washer, flat washers, and
blades from the spindle shafts.
Replace
1. Put the blades, flat washers, lock washers, and the
bolts back on the spindle shafts.
2. Tighten the bolts to a torque of 115-120 lbf-ft
(156-162.6 N•m).
3. Replace the ignition wire on the spark plugs.
Sharpen the Mower Blades
CAUTION: DO NOT sharpen mower blades
while on unit. An unbalanced mower blade will
cause excessive vibration and eventual
damage to unit. Check mower blade balance
before reinstalling blades.
NEVER weld or straighten bent blades.
1. Remove mower blade from unit.
Discard mower blade if:
• More than 1/2 in. (1.27 cm) of metal is removed.
• Air lifts become eroded.
• Blade is bent or broken.
2. Sharpen mower blade by removing an equal
amount of material from each end of mower blade.
DO NOT change angle of cutting edge or round the
corner of the mower blade.
3. Check mower blade balance.
Slide mower blade on an unthreaded bolt. A
balanced blade should remain in a horizontal
position. If either end of mower blade moves
downward, sharpen the heavy end until blade is
balanced.
4. Install mower blade(s) on unit.
5. Tighten the bolts to a torque of 115-120 lbf-ft
(156-162.6 N•m).
DO NOT Sharpen to This Pattern
2
DISCARD if More
Than 1/2 in. (1.27 cm)
3
4
Sharpen to This Pattern
1. Cutting Edge
2. Square Corner
BATTERY
WARNING: AVOID INJURY. Read and
understand entire Safety section before
proceeding.
WARNING: Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to
cause cancer and reproductive harm. Wash
hands after handling.
Unit comes equipped with a maintenance-free battery
that requires no regular maintenance except cleaning the
terminals.
Remove Battery
1. Shut OFF engine. Enage parking brake. Remove
the ignition key.
2. Place seat in the service position (See
Maintenance Schedule on page 15).
3. Disconnect cables from battery (negative, then
positive) (Figure 8).
4. Remove hold down and remove battery.
Replace Battery
1. Replace battery and secure with battery hold down.
2. Reconnect cables to battery (positive, then
negative). Position boot over positive terminal.
GB - 17
4
1
3. Air Lift Erosion
4. Air Lift
Figure 7
1
OT0792