Diagnose Mower Cuts Unevenly; Diagnose Power Take-Off (Pto) Clutch - Husqvarna Z400 Series Service Manual

Diagnose Mower Cuts Unevenly

Diagnostic Checks
Are tires inflated to
14-16 psi (96-110 kPa)
(0.96-1.1 bar)?
Are anti-scalp wheels
in the same hole
location?
Are blades sharp and
balanced?
Is the mower deck
adjusted correctly?
Are mandrels and
pulleys fastened down
correctly?
Are mandrel bearings
in good operational
condition?
Z400 Series
Results
YES: Go to next check.
NO: Adjust tire
pressure.
YES: Go to next check.
NO: Adjust anti-scalp
wheels as
necessary. See
"Adjust Mower
Deck Anti-Scalp
Wheels" on
page 4-4.
YES: Go to next check.
NO: Sharpen and
balance blades.
See "Sharpen
Mower Blades" on
page 5-3 and see
"Balance Mower
Blades" on
page 5-3.
YES: Go to next check.
NO: Adjust mower
deck. See "Adjust
Mower Deck" on
page 4-2.
YES: Checks complete.
NO: Tighten mandrel
and pulley
fasteners.
YES: Go to next check.
NO: Replace mandrels
as necessary. See
"Remove and
Install Mandrels"
on page 5-5.
Diagnose Power Take-Off (PTO)
Clutch
There are five major components that make up the power
take-off (PTO) assembly:
• Output pulley
• Armature
• Rotor
• Brake plate
• Field assembly
The PTO is activated by electric actuation and transmits
torque mechanically. When the PTO switch is in the up
(engaged) position, voltage is applied to the PTO coil.
When the PTO coil becomes energized, it creates a
magnetic flux which reduces the armature air gap and
magnetizes the rotor. When the rotor is magnetized, the
rotor acts on the brake plate. With the brake plate
applied, rotational torque is transmitted from the engine
crankshaft to the output pulley.
Diagnostic Checks
Is the power take-off
(PTO) clutch free and
clear of debris and oil?
Is the PTO switch
operating correctly?
See "Power Take-Off
(PTO) Switch Test" on
page 6-23.
Is the PTO clutch
operating correctly?
See "Power Take-Off
(PTO) Clutch Test" on
page 6-25.
7-7
TROUBLESHOOTING
Results
YES: Go to next check.
NO: Clean PTO clutch
as needed.
YES: Go to next check.
NO: Repair or replace
PTO switch as
necessary.
YES: Checks complete.
NO: Replace PTO
clutch as
necessary.