Cadillac 2013 Caddilac CTS Owner's Manual page 330

If your vehicle is equipped with
all-wheel-drive, this is an additional
system that needs lubrication.
It is not necessary to regularly
check the transfer case fluid unless
you suspect there is a leak or you
hear an unusual noise. A fluid loss
could indicate a problem. Have it
inspected and repaired.
1. Drain Plug
2. Fill Plug
To get an accurate reading, the
vehicle should be on a level
surface.
If the level is below the bottom of
the filler plug hole, located on the
transfer case, you'll need to add
some lubricant. Add enough
lubricant to raise the level to the
bottom of the filler plug hole. Use
care not to overtighten the plug.
Refer to the
to determine what kind
of lubricant to use. See
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be
sure there is enough room
around the vehicle.
.