2005 Mercury Mariner Fluid Specs
by John Walker
Knowing your fluid specifications gives you the opportunity to monitor your vehicle and keep it in good running order. The 2005 Mercury Mariner comes stock in two engine sizes: a 2.3-liter four-cylinder engine and a 3.0-liter six-cylinder engine. The factory-recommended fluid types and levels encompass oil and transmission, transfer case and rear differential, along with the various hydraulic systems.
Oil and Transmission
Both engines use synthetic multi-vehicle automatic transmission fluid (ATF) and SAE 5w20 engine oil. The 2.3-liter calls for 4.6 quarts of engine oil whereas the 3.0-liter uses 6 quarts. Total fill for the transmissions on both engines is 10.1 quarts of ATF. Always check the transmission fluid after running the engine to operating temperature and while the vehicle is running. Check engine oil with the vehicle off but the engine warm.
Transfer Case and Differential
Use the same fluids as in the transmission in the transfer case. The differential needs SAE 80w90 synthetic gear oil. Both units use fill plugs located near the top quarter of the case. Fill the units until the fluid is just beneath the opening on the case. Use an allen wrench to test the level of fluid. Insert the short end of the allen wrench into the opening and remove. The tip should show just a little bit of fluid when case is full.
Hydraulic Systems
The 2005 Mariner uses brake, clutch and power steering hydraulic systems. The systems each use a reservoir marked with a full line. Fill to the full line when filling and make sure the fluid does not drop beneath half-full when bleeding the various systems. The power steering system uses standard power steering fluid. Use DOT-3 brake fluid in the brake and clutch reservoirs.
