Toro 21" Front Wheel Drive; Rear Wheel Drive; Steel & Cast Deck Toro & Lawn-Boy Mowers Belt Replacement; Cast Deck Mowers With 3 Speed Transmission - Toro 20330 - Low Wheel Walk Power Mower Service Manual

SELF-PROPEL BELT REPLACEMENT
There are several different procedures for replacing
the self propelled belt. Mowers with a blade clutch
mechanism are the most complex as parts of that will
need to be removed to access the self propel belt.

Toro 21" Front Wheel Drive

See Worm Drive Transmission page 1-1.
These mowers usually have a model number that starts
with 16xxx.
Remove the belt cover, push the top of the transmission
to the rear to create slack in the belt and remove the
belt. Push the belt towards the engine. Drain fuel and oil
to prevent spillage and tip the mower on its side, air fi lter
side up. Slip the belt off the crankshaft pulley. In some
cases there might not be enough clearance between
the blade and mower housing. It might be necessary to
remove the blade to slip the belt off.
Reverse the process to assemble.
22" Front Wheel Drive
See Single Speed Bevel Gear Transmission page 2-1.
These mowers usually have a model number that starts
with 200XX.
Drain the fuel and oil before you tip the mower on its
side. To remove the belt cover, tip the mower to access
the two mounting screws from the bottom. There are
belt guides on both the transmission and around the
crankshaft. DO NOT bend them or force the belt out
from under the guides. Loosen or remove the mounting
screws to pivot the belt guides out of the way. If the belt
guides are bent or out of place the belt will have a larger
tendency to jump and may not disengage properly. It
may be necessary to remove the blade to replace the
belt. Do not force the new belt between the blade and
mower housing. A nick or cut in the new belt can cause
premature failure.
8-2

22" Rear Wheel Drive

These are steel deck mowers, made in both Toro and
Lawn-Boy brands.
In order to replace the self propel drive belt the
transmission must be removed from the chassis. This
is necessary to access the pulley and belt guide on
top of the transmission. See Single Speed Bevel Gear
Transmission, Rear Wheel Drive Models, Transmission
Removal and Belt Replacement, see page 3-10.
Do not bend the belt guides or force the belt between
the pulley and belt guide. Drain the gas and oil before
tipping the mower to avoid fuel spillage. Remove or
loosen the belt guide mounting screws and move the
belt guide out of the way. A bent belt guide will cause an
increased tendency for belt jumping and damage.
21" Steel and Cast Deck Toro and Lawn-Boy
Mowers Belt Replacement
Drain the gasoline and oil before tipping the mower
to avoid fuel spillage. Remove the belt cover. Loosen
or remove the belt guides so the belt can be replaced
without forcing. See the Single Speed Spur/Bevel Gear
Transmission section for a typical transmission and drive
layout, see page 2-2.
21" Cast Deck Mowers with 3 Speed
Transmission
Made in both Toro and Lawn-Boy brands.
To replace the belt, drain both the gasoline and oil from
the engine. Remove the belt cover, just behind the
engine on top of the mower, to access the transmission.
Loosen or remove the belt guides so the belt can be
replaced without forcing. See the section on the three
speed transmission starting on page 4-1.
WPM Drive Systems Manual