
Copyright Meritor, Inc., 2020
MM-0861 / Revised July 2020
Page 94
Printed in USA
9
Troubleshooting
PTO Does Not Engage/Disengage Diagnostics
Figure 9.4
Check air connection to
PTO shift port.
Return the vehicle
to service.
Check indicator light,
and engagement and
disengagement sensors
for correct operation.
Check the available air pressure.
The transfer case requires at
least 60 psi (4.14 bar) at all
times to operate correctly.
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Replace faulty indicator
light or sensor, then try
to shift PTO.
Correct system air pressure.
Refer to the vehicle
manufacturer’s instructions.
Check the piston cylinder on the
PTO. Clean the air supply system.
Refer to vehicle manufacturer’s
instructions. Check that the PTO
engages correctly.
Return the vehicle to service.
Check the PTO for leaks.
Reassemble and install the PTO on the
transfer case. Road test the vehicle to
confirm the problem is corrected.
No
Remove the PTO from the transfer case.
Disassemble the PTO and inspect the
bearings, shift collar, shift fork declutch
bore and return spring for damage.
Repair all damaged components.
Verify the PTO engages and
disengages correctly.
Light or
sensor
faulty?
Air
pressure 65 psi
(4.48 bar) or
more?
Air
system
contaminated?
4001528d
PTO
shifts
correctly?
PTO
shifts
correctly?
Return the vehicle
to service.
Return the vehicle
to service.
Return the vehicle
to service.
Summary of Contents for MTC-4208X Series
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