Walker MDD (20.9 HP) - Manual (Page 67)

63
Maintenance Instructions
CHECKING/SERVICING
NOTE: Blades can be sharpened with an elec-
tric blade sharpener, conventional electric grind-
er, or a hand file.
Mower Blade Profile For Sharpening
6. Check blade balance by positioning the blade
horizontally on a blade balancer or use a nail
or shaft through the center hole. If either end of
the blade rotates downward, grind (remove)
metal on that end until the blade will
balance. The blade is properly balanced when
neither end drops. Balance of a blade is gener-
ally maintained by removing an equal amount of
material from each end of the blade when
sharpening.
Blade Balanced on Magnetic
Wall-Mounted Balancer
7. Mount the blade with wing tips pointing up into
the housing. Reinstall the blade, washer, lock
washer, and nut. Tighten the nut to 60 ft-lb
(81.3 N·m).
NOTE: When reinstalling blades on GHS models,
remember, the blades turn toward each other
(counter-rotate) and the RH and LH blade cannot be
switched. Check for proper blade rotation before in-
stalling blades on the deck. Refer to Blade Rota-
tion for GHS Mower Deck illustration shown in
Clogging Checklist in
Operating Instructions for
correct blade rotation.
Drive Belts
Raise the body and inspect the condition of the five
(5) belts (4 belts on SD models) every 25 hours of
operation - engine PTO drive, jackshaft drive, hydro-
static ground drive, GHS blower drive, and engine
fan belt. If the belts show signs of cracking or de-
teriorating, the belts should be replaced. Refer to
REPLACING/REPAIRING the Drive Belts in this
section.
Mower Deck Gearbox Oil Seals
The mower deck gearbox seals should be inspected
every 25 hours for evidence of oil leaking; particu-
larly the lower oil seal on the blade drive gear-
box. This seal is protected by the trash guard on the
blade hub and seal protector plate on the housing,
but is still vulnerable to seal damage due to operat-
ing in an adverse environment. The mower blade
must be removed for inspection of the seal, so it is
recommended to inspect the gearbox seals when
blades are removed for sharpening. If an oil leak
is noted, the seal should be replaced and the gear-
box assembly relubricated. Refer to Mower Deck
Gearbox Lubrication in this section.
CAUTION
ALWAYS wear eye protection and gloves
when sharpening a blade.
30°
Do Not Grind or
Sharpen on Underside
Sharpen at
Original 30° Angle
Intersection
Wear Area
Wing
Tip
Blade Balancer