1998 GMC Suburban Owner's Manual - Page 318

When the differential is cold, add enough lubricant to raise the level to 1/2 inch (12 m m ) 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 toUse Refer to the Maintenance Schedule to determine what kind of lubricant to use. See "Recommended Fluids and Lubricants" in the Index. A 50/50 mixture of water and DEX-COOL@ coolant will: Give freezing protection down to -34°F (-37°C). 0 Give boiling protection up to 265°F (129°C). Protect against rust and corrosion. Help keep the proper engine temperature. Let the warning gages work as they should. 0 0 NOTICE: When adding coolant, it important that you use is only DEX-COOL@(silicate-free) coolant. If coolant other thanDEX-COOL is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 30,000 miles (50000 km) or 24 months, by whichever occurs first. Damage caused the use of coolant other thanDEX-COOL@ is not covered by your new vehicle warranty. Engine Coolant The cooling s stem in your vehicle is filled with DEX-COOL engine coolant. This coolant is designed to remain in your vehicle for 5 years or 150,000 miles (240 000 km), whichever occurs first, if you add only DEX-COOL@extended life coolant. 2 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. -- 6-26