Adjusting The Idler Pulley; Replacing The Drive Belt - Toro 30555 Operator's Manual

Adjusting the Idler Pulley

The idler pulley applies force against the belt so that power
can be transmitted to the blade pulleys. If the idler is not
tensioned against the belt with sufficient force, maximum
power will not be transmitted to the pulleys. Initial tension
on a new belt requires 25 to 30 ft.-lb. (34 to 41 N⋅m) of
torque on the large nut, which applies force against the belt.
As the belt wears and loosens, 20 to 25 ft.-lb. (27 to
34 N⋅m) of torque on the large nut is required. If the idler is
not adjusted to these specifications, an adjustment is
necessary.
1. Position the machine on a level surface, lower the
cutting unit, engage the parking brake, put the traction
pedal in neutral, the PTO lever in the Off position, shut
the engine off, and remove the ignition key.
2. Release and unhook the latches securing the center
cover to the top of the cutting unit. Remove the cover
from the cutting unit.
3. Loosen the 2 nuts securing the idler plate in place.
Using a socket and torque wrench, tighten the idler
adjusting nut to 25–30 ft.-lb. (24–41 N⋅m) (Fig. 33).
2
3
2
Figure 33
1. Idler plate
2. Nuts (2)
4. Hold the torque against the belt and tighten the 2 nuts so
that the idler plate is held securely in place. Release the
idler adjusting nut. Install the cover and secure the
latches.
1
3. Idler adjusting nut
22

Replacing the Drive Belt

The blade drive belt, tensioned by the adjustable idler, is
very durable. However, after many hours of use, the belt
will show signs of wear. Signs of a worn belt are: squealing
when belt is rotating, blades slipping when cutting grass,
frayed edges, burn marks, and cracks. Replace the belt if
any of these conditions are evident.
1. Position the machine on a level surface, lower the
cutting unit, engage the parking brake, put the traction
pedal in neutral, the PTO lever in the Off position, shut
the engine off, and remove the ignition key.
2. Release and unhook the latches securing the covers to
the top of the cutting unit. Remove the covers.
3. Loosen the 2 nuts securing the idler plate in place and
remove the old belt from the pulleys.
4. To install a new belt, the gear box base must be
removed. To do this, remove the 4 carriage bolts and
locknuts holding the gear box base.
5. Install the new belt around the gear box pulley, spindle
pulleys, stationary idler pulley, and adjustable idler
pulley (Fig. 34).
1
Figure 34
1. Adjustable idler pulley
6. Install the gear box base with the carriage bolts and
locknuts.
7. Using a torque wrench, adjust the tension of the idler
pulley against the belt; refer to Adjusting the Idler
Pulley, page 22.
8. Install the covers and secure the latches.
2
2. Gear box pulley