What is Differential Repair? Do I Need it?

If you’re like most people, you don’t necessarily know how all the different parts of your vehicle work, or even where they are. What you do know is when it’s working and often, though not always, when it’s having trouble.

Sure, you know where your tires are, how to fill up with gas, and maybe how to change your oil. However, do you know where your differential is? Or what it is, what it does, and how it works? Even more, do you know when it needs to be repaired and the symptoms that would alert you to it?

What is a Differential?

A differential is a mechanical part that makes it possible for your wheels to rotate at different speeds when turning a corner. This is important because the outside wheels have a bit more distance to cover than the inside wheels when turning, and the differential lets them turn at different speeds smoothly without the wheels binding or hopping.

On front-wheel drive vehicles, the differential is done by the transaxle. On all-wheel drive vehicles there is a differential on both axles, and also have either a center differential or a transfer case to compensate for differences in speed between the front and rear. The differential is on the rear axle in rear-wheel drive vehicles. The differential is easy to see on lifted trucks—it’s the bulge-shaped case in the middle that some will call a pumpkin, due to its similarity in shape.

Symptoms of a Differential Needing Repairs

Lubrication plays an important role in the differential, just as it does in other parts of your vehicle. It protects the internal metal parts from damage due to overheating and metal-to-metal contact. The fluid in the differential is called differential oil, also referred to as gear oil.

Similar to automatic transmission fluid and the same oil used for manual transmissions, differential oil can put the interior differential components at risk if it becomes dirty, contaminated, or is past its expected service life.

If the gears in the differential are whining or howling and get louder with an increase in speed, your differential is at risk of failing if ignored. This is due to the gear oil being either low or very dirty. It should be inspected right away to prevent serious damage. Rumbles or clunks around the axle when accelerating or coasting or the vehicle feeling sluggish, especially at low speeds, also indicate a problem with the differential.

Most manufacturers recommend the differential fluid be changed every 30,000 – 60,000 miles. This is not a DIY job due to the location of the differential, the need to dispose of the used oil properly, a gasket that will need replacing, and the need to clean the internal parts of contaminants before reassembly and refilling with oil.

Come for an Inspection

Bring your vehicle to Advanced Transmission for our free TrueTest Inspection and we will be able to let you know if it’s time to change the fluid in your differential, or if a repair is needed.

If you have any of the symptoms that your differential is having problems, don’t wait to come in.