Cars that need differential repairs show symptoms of shaking, bumping and making hopping motions while driving. Differentials exist on all cars, and work to transfer energy from the engine to the wheels. They also provide stability while cornering; a suddenly unsteady, bouncy ride may indicate that it is time for a new differential.
Vehicles with four-wheel drive have differentials in the front and rear while rear-wheel drive cars only have them in the back. Regardless of location, the symptoms of a failing differential are the same. In addition to excessive vibration, problematic differentials may cause a squeaking or grinding noise. When differentials do not work properly, car tires move at the same speed, which makes them unstable. They may start shaking or feel unsteady while cornering and maneuvering down straight roads.
As with other car repairs, the type of driving surface, nature of driving purpose and frequency of driving impact the frequency of differential repair needs. High volumes of driving wear out differentials more quickly, as does driving on rough terrain, such as dirt roads.
To keep differentials from causing trouble, drivers can have differential fluid levels checked during regular tune-ups. Mechanics can check to make sure fluid levels are sufficient to keep components and gears from wearing down. Like other car services, a differential repair requires an appointment with a mechanic.