ELECTRICAL
8-3Toro GrandStand Service Manual
8
Electric (PTO) Clutch
Purpose
This clutch electrically controls the engagement and
disengagement of the Power Take Off (PTO) pulley,
which drives the mower deck belt.
How It Works
The PTO clutch is composed of three major compon-
ents: the eld, the clutch plate, and the friction plate.
The clutch plate always turns with the engine. The eld
is a coil of wire on an iron core, which becomes an
electromagnet when power is applied.
The friction plate is the only piece that can slide up and
down on the crankshaft axis. It is normally spring-loaded
so that it is not in contact with the clutch plate and is
pressed against the brake material opposite the clutch.
When power is applied, the friction plate is drawn toward
the clutch plate and the two rotate as one.
Location
The electric clutch is located on the PTO end of the
engine crankshaft, under the machine (Fig. 1433).
Fig. 1433 IMG-0570a
Coil Resistance Measurement
1. Disengage the PTO, set the parking brake, turn the
ignition OFF, and remove the key.
2. Disconnect clutch wire connector from the wire
harness.
3. Set the multimeter or volt/ohm meter to check
resistance (ohms).
4. Connect the multimeter leads to the wires in the
clutch connector (Fig. 1434).
5. The meter should read between 2.40 ohms and
3.40 ohms. If the reading is above or below these
readings, the eld has failed and needs to be
replaced. If the reading is between these two limits,
measure the clutch current draw (next).
Fig. 1434 coil resist measurmt
Testing
If the electric PTO clutch is not engaging or is suspected
as a cause of electrical problems, use the trouble-
shooting procedures below. These procedures will help
you determine if the clutch has failed or is the cause of
the electrical problem.
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