Maintenance & Repair
Rear differential maintenance and changing the fluid is a good way to prevent pre mature failure of gears and bearings in your differential. A regular maintenance routine includes inspecting the gear lubricant level and condition. You can check your owner’s manuals for specifications as well as the types of fluids to be used.
Rear Wheel Drive
In the case of rear wheel drive vehicles different types of gear oil are used in different makes and models. Since there is no filter, inside fluid can become contaminated with metal flakes and moisture.
Metal Particles, Special Lubricants, & Early Warning Signs
Most rear differentials will have magnets either mounted inside or as part of the drain plug to help remove metal particles from the circulation lubricant. In some limited slip rear differentials special lubricants that contain a friction modifier are required. Failure to use this special recommended fluid can cause drivability problems and increased wear.
As with many parts on the car rubber seals are susceptible to wear and leakage. The rear differential contains a few of these lip type seals. Fluid leak from this area should be repaired before lack of lubrication damages internal components.
Rear axle seals are also made out of rubber. A leaking rear seal can cause the same type of problems with lack of lubrication. But more importantly a rear axle seal leak can dump fluid into your rear brake pads or shoes. This type of problem can increase stopping distances and cause other problems. On many rear differentials the cover that fits on the back is another point of a possible leak to develop.
Rear differential maintenance is important because the entire assembly does not carry more than a few quarts of lubricant. Even a small leak that goes unnoticed can cause other problems. An occasional visual inspection of the parts mentioned above can provide an early warning and save you from expensive repair costs.