[Phoenix]

Does the Differential on an Ordinary Car Need Regular Maint?

Yes, they do. It is not as frequent as the engine or automatic transmission fluid; but periodically, you should have a mechanic (or you can do it yourself) check the fluid level, and per the maintenance schedule, drain and refill the differential oil. Locking differentials (e.g. "posi-traction") take different oil than regular differentials, so make sure you use the right kind for your car. The wrong kind can ruin the rear-end. On most rear drive cars and trucks, the oil is checked by removing the fill plug and sticking your finger in to see if the fluid is up to the fill hole.

 

[Phoenix]

Does the Differential on an Ordinary Car Need Regular Maint?

Correction: "Limited-slip differentials" not "locking differentials". Limited slip differentials like "posi-traction" have a clutch between the gears the drive the two wheels. Instead of the wheel with the least resistance getting all the torque, the clutch drives the other wheel, too. Low fluid level or driving with different size wheels and tires on the two wheels will cause the clutch to slip all the time and burn it out.