1998 Pontiac Firebird Owner's Manual - Page 280

How to Check The proper fluid should be added the level is below if the STEP mark on the reservoir. See the instructions on the reservoir cap. Limited-Slip Differential To add lubricant when the level low, use SAE 75W-90 is Synthetic Gear Lubricant (GMP r No. 12378261) or at equivalent meeting GM Specification 99861 15. To completely refill after draining, add ounces (118 ml) 4 of Limited-Slip Differential Lubricant Additive (GM P r No. 1052358) or equivalent. Then to the bottom at fill of the filler plug hole with Synthetic Gear Lubricant. Rear Axle When to Check and Change Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant and when to changeSee it. "Scheduled Maintenance Services" in the Index. Engine Coolant The cooling s stem in your vehicleis filled with DEX-COOL engine coolant. This coolant is designed How to Check Lubricant to remain in your vehicle 5 years or 150,000 miles for (240 000 whichever occurs first, if you add only If the level is below the bottom of the filler plug hole, you'll need to add some lubricant. Add enough lubricant DEX-COOL extended life coolant. to raise the level to the bottom the filler plug hole. of The following explains your cooling system and how to add coolant when is low. If you have a problem it What to Use with engine overheating or you needto add coolant to if your radiator, see "Engine Overheating" in the Index. Standard Differential 8 kmb Use SAE 75W-90 Synthetic Gear Lubricant (GMa t Pr No. 12378261) or equivalent meeting GM Specification 9986 115. 6-27