Drain & Replace The Oil; Transfer Case Inspection - Meritor MTC-4208X Series Service Manual

10 Lubrication & Maintenance
4. The oil level must be even with the bottom of the fi ll plug.
If oil fl ows from the fi ll plug port when the plug is
loosened:
The oil level is too high. Drain the oil to the bottom of the fi ll plug
hole. Ensure cooler oil line routing prevents back fl ow to the
transfer case sump
NOTE: Oil can drain back from the oil cooler, giving the
appearance of an over full condition.
If the oil level is below the fi ll/level plug hole:
Add SAE Grade full synthetic 40W or 50W oil, Meritor
Specifi cation 0-81, until oil is even with the bottom of the fi ll hole.
5. Install and tighten the fi ll plug to 35-50 lb-ft (47-68 N∙m).
6. Test drive the vehicle for at least one mile (1.6 km). Allow the oil
to settle for fi ve minutes and recheck the fl uid level. Top off the oil
level by adding oil to the fi ll opening. Reinstall and tighten the fi ll
plug to 35-50 lb-ft (47-68 N∙m).
MAGNETIC
DRAIN PLUG
STANDARD MODEL FRONT COVER
Figure 10.5
MM-0861 / Revised July 2020
Page 100
OIL FILL
PLUG
FRONT
4007128a
Drain & Replace the Oil
1. Park the vehicle on a level surface. Place a large container under
the transfer case.
2. Remove the magnetic drain plug from the bottom of the transfer
case. Drain and discard the oil correctly. Clean the plug. Figure
10.5.
3. Install and tighten the drain plug to 35-50 lb-ft (47-69 N∙m).
Clean the area around the fi ll plug. Remove the fi ll plug from the
transfer case.
4. Add SAE Grade full-synthetic 40W or 50W oil, Meritor
specifi cation O-81, into the transfer case until the oil level is even
with the bottom of the fi ll plug hole. Install and tighten the fi ll plug
to 35-50 lb-ft (47-68 N∙m).
5. Test drive the vehicle for at least one mile (1.6 km). Allow the oil
to settle for fi ve minutes and recheck the fl uid level. Top off the oil
level by adding oil to the fi ll opening. Reinstall and tighten the fi ll
plug to 35-50 lb-ft (47-68 N∙m).

Transfer Case Inspection

Visually inspect the transfer case daily for any leaks. The oil level
should be inspected every 1,000 miles (1069 km), 100 hours or every
month, whichever comes fi rst. In addition, the transfer case should be
inspected for leaks and the correct oil level before and after extended
time high speed road trips. Areas to inspect are:
• Cooler lines and fi ttings
• Seals
• Breather
• Fill and drain plugs
• Pump inlet tube and fi ttings
• Gaskets and shims
• During the inspection visually check to ensure the transfer case
oil level is to the bottom of the oil fi ll hole.
Copyright Meritor, Inc., 2020 Printed in USA