Specifications

maintenance operation for the shift unit lubricant
changing procedure.
12. Remove the chocks, then drive the vehicle, un-
loaded, for 1 or 2 miles (2 or 3 km) at speeds
not to exceed 25 mph (40 km/h), to thoroughly
circulate lubricant throughout the carrier and
housing assemblies.
Two-Speed-Axle Shift Unit
Lubricant Changing
Dana Spicer and Meritor Axles
1. Remove the shift unit housing cover. See Fig. 6.
Drain and discard the old lubricant. Discard the
housing cover gasket.
2. Thoroughly wash the axle shift parts and housing
cover, and allow them to air dry.
3. Install the housing cover and a new cover gas-
ket. Tighten the housing cover capscrews 7.5 to
9.2 lbf·ft (10.2 to 12.5 N·m), then remove the oil
fill plug from the cover.
IMPORTANT: When the ambient temperature is
above 0°F (–18°C), use SAE 10 heavy-duty en-
gine oil, API service classification SD (sulfated
ash content must not exceed 1.85%). When the
ambient temperature is below 0°F (–18°C), use
one part kerosene to three parts SAE 10 heavy-
duty engine oil, API service classification SD
(sulfated ash content must not exceed 1.85%).
This cold-weather mixture can be safely used
up to 32°F (0°C).
Commercially available automatic transmission
fluid may be used in place of SAE 10 engine oil.
Automatic transmission fluid can be used for all
temperatures; do not mix it with kerosene. To
prevent component damage, do not mix engine
oil and automatic transmission fluid.
4. Fill the shift unit housing through the oil fill hole
until specified lubricant is level with the bottom of
the opening.
5. Apply a small amount of Loctite
®
242, or equiva-
lent sealant, to the threads of the fill plug. Install
the plug finger-tight on the rear axle housing.
Use a wrench and tighten it an additional 1-1/2
turns.
35–02 Axle Breather and Axle
Lubricant Level
Inspection
Dana Spicer Axle
CAUTION
Failure to keep the rear axle filled to the proper
level with the recommended lubricant can result in
rear axle damage.
1. Park the vehicle on level ground, apply the park-
ing brakes, and chock the tires.
2. If the vehicle has just been driven, allow a few
minutes for the lubricant to settle.
3. Clean the oil fill plug and area surrounding it,
then remove the plug from the fill hole (see
Fig. 1), or from the standpipe (if so equipped)
installed in the fill hole.
IMPORTANT: A lubricant level close enough to
be seen or touched is not sufficient. It must be
level with the bottom of the fill hole (see
Fig. 3),
or the top of the standpipe opening.
4. Lubricant should be level with the bottom of the
fill hole (see
Fig. 3), or with the top of the stand-
pipe opening. If low, check the axle for oil leaks,
f350021a
08/06/93
1
2
3
1. Housing Cover Gasket
2. Oil Fill Plug
3. Shift Unit Housing Cover
Fig. 6, Two-Speed-Axle Shift Unit
Rear Axle 35
Century Class Trucks Maintenance Manual, April 2005 35/5