Your car’s engine provides the grunt that propels you down the road, but it isn’t the only star of the show. All that horsepower is worthless if it can’t get to the wheels, and that’s where the rest of your vehicle’s drivetrain comes in. Depending on your vehicle’s particular configuration, several components may be responsible for transferring this power to the ground. 

Of these components, the differential is often the most neglected. Many drivers may not even be aware of its existence. Keep reading to learn about the vital role this component plays in your car’s operation. 

Understanding the Drivetrain 

Your car’s differential is part of a larger power delivery system known as the drivetrain or driveline. Your drivetrain connects the source of your car’s power (the engine) to its destination (the wheels). Depending on your car’s configuration, the drivetrain may consist of a transmission, driveshaft, and one or more differentials. 

Your engine produces power by rotating its crankshaft. If your engine were connected directly to your wheels, then the wheels would always turn at the same speed as the crankshaft. Your transmission uses gears to adjust the output speed of your engine up or down, helping to keep your engine safely within its power band at all speeds. 

For most cars, the transmission is the first of two gear sets used to step the engine’s power down. A final drive gear steps the power down one more time before the differential transmits it to the wheels. The final drive ratio allows manufacturers to better tune their vehicles for performance or efficiency. In most cars, the differential gear set and final drive gear set are contained within the same housing. 

Understanding the Differential

Although your transmission and final drive gear adjust engine power up or down as necessary, they still produce only a single output. Your differential splits the power between your car’s drive wheels, allowing them to rotate at different speeds as necessary. 

To understand why your tires must rotate at different speeds, imagine your car as it goes around a corner. Since the inner wheels are traveling a shorter distance than the outer wheels, they must rotate at a different speed. Without your differential to allow this, your vehicle’s tires would wear more quickly, and your stability at high speeds would be compromised. 

Note that all modern consumer vehicles use differentials, but front-wheel drive vehicles often integrate the differential, transmission, and final drive gear into a single unit called a transaxle. Rear-wheel drive and all-wheel drive cars typically have discrete differential components for each set of drive wheels. 

Understanding What Can Go Wrong

As with any other essential vehicle component, recognizing the signs of a failing differential can help to keep your car on the road and save you money over the long run. Although differential designs can vary significantly, differential problems usually present in one of three ways: 

  • Noticeable gear grinding, both when stopped and when in motion. 
  • Fluid leaks that may produce small drips or puddles on the ground. 
  • Unusual noises when accelerating or braking quickly. 

If you notice any of the above symptoms, you should always rely on a qualified mechanic to perform an inspection. In some cases, differential problems can be the result of fluid leaks, and quickly addressing the issue can prevent further damage. With differential replacement costs ranging as high as $500, the savings can be significant. 

If you suspect a problem with your car’s differential, then DeMers Automotive can help. Schedule an appointment with us today to get your car’s drivetrain back into perfect running condition and to get you back on the road.