Final answer:
The correct lubricant for the front axle on a rear-wheel-drive car is wheel bearing grease, which is designed to handle the specific conditions of wheel bearings.
Step-by-step explanation:
The correct lubricant for the front axle on a rear-wheel-drive car is typically wheel bearing grease. Motor oil and transmission fluid are not appropriate for this application as they are designed for the engine and transmission components, respectively. White lithium grease can be used for a variety of applications, but when it comes to the high-load environment of wheel bearings, wheel bearing grease specifically formulated for this purpose provides the best protection and longevity.
Why Use Wheel Bearing Grease?
Wheel bearing grease is designed to withstand high-temperature and high-pressure conditions that front axle wheel bearings encounter. It usually contains additives that protect against wear, corrosion, and water washout. The consistency of the grease helps it stay in place to continuously lubricate the wheel bearings, which is vital for their function and the safe operation of the vehicle.