Meritor MTC-4208X Series, Service Manual, Page: 82 / 120

Copyright Meritor, Inc., 2020
MM-0861 / Revised July 2020
Page 78
Printed in USA
6 Assembly
Optional Oil Pressure Test & Oil Fill Check
1. Park the vehicle on a level surface and set the parking brake.
WARNING
THE TRANSFER CASE AND OIL LINES MAY BE HOT. USE
CARE TO AVOID GETTING BURNED.
2. With the vehicle on a level surface, fi ll the transfer case to the
bottom of the fi ll hole with SAE Grade full-synthetic 40W or 50W
oil, Meritor specifi cation O-81.
3. Install the 3/8” female JIC fi tting onto one end of the 10’ (3.05
meter) pressure hose and the pressure gauge onto the other end.
4. Connect the female fi tting to the unused port of the diagnostic tee
fi tting. Figure 6.51.
5. Route the gauge to a position where it can be viewed in the cab of
the vehicle.
6. Verify the parking brake is set.
7. Start and idle the vehicle for one minute with the pressure
gauge connected. If necessary, refer to the original equipment
manufacturer (OEM) instructions to start the vehicle.
8. Verify the vehicle primary and secondary air pressures are at least
90 psi (6.2 bar).
9. Move the transfer case toggle switch to the Neutral (middle)
position. The transfer case will not shift into Neutral if the air
pressure is below 90 psi (6.2 bar). If necessary, refer to the
original equipment manufacturer (OEM) instructions to start the
vehicle.
10. Place the transmission into drive.
11. Verify the transmission is in the highest range possible. If not,
refer to the vehicle operator’s manual for shifting instructions.
DANGER
KEEP CLEAR FROM UNDER THE VEHICLE WHEN CHECK-
ING THE INPUT SHAFT TO PREVENT SERIOUS PERSONAL
INJURY.
12. With the transmission in High, have an assistant outside the
vehicle verify the input shaft to the transfer case is turning. Keep
clear from under the vehicle when checking the input shaft. If the
input shaft is not turning, the transfer case is not in Neutral. If the
transfer case is not in Neutral, perform the following procedure.
a. Shift the transmission back into Neutral.
b. Shift the transfer case to high and low range and back to
Neutral.
c. Attempt to place the vehicle back into drive and repeat the
procedure until the transfer case goes into Neutral.
CAUTIONS
RUN THE ENGINE FOR NO LONGER THAN ONE MINUTE. DO
NOT REPEAT THE TEST OR DAMAGE TO COMPONENTS CAN
RESULT.
WHEN PERFORMING THE OPTIONAL OIL PUMP PRESSURE
DIAGNOSTIC CHECK, TEST THE SYSTEM FOR NO LON-
GER THAN ONE MINUTE. IF THE OIL PRESSURE IS NOT AT
LEAST 3 PSI (0.21 BAR) AFTER ONE MINUTE, TURN THE
VEHICLE OFF. DO NOT REPEAT THE TEST. DAMAGE TO
COMPONENTS CAN RESULT. CALL THE MERITOR ON-
TRAC™ CUSTOMER CALL CENTER AT 866-668-7221 FOR
ASSISTANCE.
13. Once the transfer case is in Neutral and the transmission is in
High, press the accelerator and run the engine at 1800-2200 rpm
for no longer than one minute or until oil pressure reaches 10 psi
(0.69 bar), whichever occurs fi rst. With the transmission in High,
observe the reading on the pressure gauge. The reading should
be 5-20 psi (0.34-1.38 bar).
If oil pressure is not at least 3 psi (0.21 bar) after one
minute:
Turn the vehicle off. Do not repeat the test or damage to
components can result. Call the Meritor OnTrac™ Customer Call
Center at 866-668-7221 for further assistance.
14. Once the test is complete, allow the engine to idle back down.
Shift the transmission back to Low.
15. Shift the transmission back to Neutral.
DANGER
SHIFT THE TRANSFER CASE INTO HIGH RANGE FOR THIS
PROCEDURE. REFER TO THE VEHICLE OPERATOR’S MAN-
UAL INSTRUCTIONS. IF YOU DO NOT SHIFT INTO HIGH
RANGE, SERIOUS PERSONAL INJURY AND DAMAGE TO
COMPONENTS CAN RESULT.
16. Shift the transfer case back into high range. If necessary, refer to
the vehicle operator’s manual instructions.
17. Turn the vehicle off. If necessary, refer to the original equipment
manufacturer (OEM) instructions.
18. Remove the diagnostic equipment.
19. Reinstall the diagnostic port cap. Tighten to 35-40 lb-ft (47-54
N∙m).
20. Check the system for leaks at all fi tting connections and transfer
case oil ports.
21. Check the oil fi ll level in the transfer case. The level should be
below the fi ll hole following the priming run.
22. Refi ll the transfer case to the bottom of the fi ll hole.