Chevrolet 1998 Tracker Owner's Manual page 261

When the differential is cold, add enough lubricant
to raise the level to 1/2 inch (12
mm)
below the filler
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to
the bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See "Recommended Fluids and
Lubricants" in the Index.
Engine Coolant
The following explains your cooling system and
how to add coolant when it is low. If you have a
problem with engine overheating, see "Engine
Overheating" in the Index.
A 50/50 mixture of water and the proper coolant will:
0
Give freezing protection down to -33°F (-36°C).
Give boiling protection up to 258
O F
(1 25
O
C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
What to Use
Use a mixture of one-half clean water (preferably
distilled) and one-half coolant that meets GM
Specification 1825-M, which won't damage aluminum
parts. You can also use a recycled coolant conforming
to GM Specification 1825-M with a complete coolant
flush and refill. If you use this mixture, you don't need
to add anything else.
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean water and the
proper coolant.