What is a Rear Differential and What Does it Do?

What is a rear differential and what does it do?  When should I get it fixed?  These questions will be answered in this post.

What is a Rear Differential?

Differential Repair in Mesa | (480) 986-7367
Differential Repair in Mesa | (480) 986-7367

First off, some vehicles have a front and rear end differential.  Differentials, either front or rear do three things as a rule.  They transfer power from the engine to the wheels.  They help to slow the transmission before it goes to the wheels, and they allow your car or truck’s wheels to all spin at different speeds, as emphasized by this article excerpt from How Stuff Works:  “Car wheels spin at different speeds, especially when turning. You can see from the animation that each wheel travels a different distance through the turn, and that the inside wheels travel a shorter distance than the outside wheels. Since speed is equal to the distance traveled divided by the time it takes to go that distance, the wheels that travel a shorter distance travel at a lower speed. ” READ MORE


How do you know when to fix your rear differential?  Listen to the sounds your car makes while you’re either accelerating or slowing down.  If you hear a lot of noises when you change speeds, you probably need to get differential repair.

How Much Does a Rear Differential Cost?

How much does a rear differential cost?  Well that depends.  A new one is obviously more than a rebuilt one, and in some cases, the rear differential will likely be covered by your warranty.  You want to get your car in for rear differential maintenance to help keep your costs down.  That way any problems can be caught early on before they become both extensive as well as pricey.

One thing that your mechanic can check is your fluid level.  If it is getting too low, sometimes this can manifest symptoms of a greater problem, just as transmission fluid can do.  So remember, if you’re a bit proactive about your auto repair, you can turn a service visit into a minor differential repair rather than a major one.

Trail Transmission
11240 East Apache Trail
Apache Junction, AZ 85120-3529
(480) 986-7367

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