Changing The Deckbelt - MTD series 780 Operator's Manual

The blades may be removed as follows.
1. Remove the deck from beneath the tractor, (refer to Cutting
Deck Removal earlier in this section) then gently flip the deck
over to expose its underside.
2. Place a block of wood between the center deck housing baffle
and the cutting blade to act as a stabilizer. See Figure 7-5.
3. Remove the hex flange nut that secures the blade to the
spindle assembly. See Figure 7-5.
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4.
Figure 7-5
To properly sharpen the cutting blades, remove equal amounts
of metal from both ends of the blades along the cutting edges,
parallel to the trailing edge, at a 25 ° to 30° angle.
iMPORTANT:
If the cutting edge of the blade has already been
sharpened to within 1%" from the edge, or if any metal separation is
present, replace the blades with new ones. See Figure 7-6.
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Figure 7-6
CAUTION:
If the cutting edge of the blade has
previously been sharpened, or if any metal
separation is present, replace the blades with new
ones.
WARNING! A poorly balanced blade will cause
excessive vibration, may cause damage to the
tractor and/or result in personal injury.
5. Test the blade's balance using a blade balancer. Grind
metal from the heavy side until it balances evenly.
NOTE:When replacing the blade, be sure to install the blade with
the side of the blade marked "Bottom" (or with a part number
stamped in it) facing the ground when the mower is in the
operating position.
CAUTION:
Use a torque wrench to tighten the
blade spindle hex flange nut to between 70 Ibs-ft
and 90 Ibs-ft.
Changing the DeckBelt
WARNING!
Be sure to shut the engine off, remove
ignition key, disconnect the spark plug wire(s) and
ground against the engine to prevent unintended
starting before removing the belt.
WARNI NG! All belt on your tractor are subject to
wear and should be replaced if any signs of wear are
present.
IMPORTANT:
The V-belt found on your tractor are specially
designed to engage and disengage safely. A substitute (non-
OEM) V-belt can be dangerous by not disengaging completely.
For a proper working machine, use factory approved belts.
To change or replace the deck belt on your tractor, proceed as follows:
1. Remove the deck as instructed earlier in this section.
2. Remove the belt covers by removing the hex washer
screws that fasten them to the deck. See Figure 7-7.
Hex Washer Screws
3.
Figure 7-7
It may also be necessary to loosen the hex nut on the left
idler pulley to get the belt off the pulley and around the
belt guard.
SECTION 7--
SERVICE