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Your car’s transmission sends power to the driven wheels, but the wheels themselves need assistance to operate effectively. If they were forced to rotate at the same speed, it would place a strain on the axle and hamper your car’s ability to turn. A differential helps prevent these issues by allowing each of your vehicle’s driven wheels to spin at a different speed.

Check out these common problems with differentials, along with the serious consequences that can result if they’re left unaddressed.

Symptoms of a Damaged Differential

Other components may show signs of damage when your vehicle has differential problems. Here a few things to look for if you suspect something’s off:

  • Worn carrier bearings. If your car makes a rumbling or whirring noise when traveling faster than 20 mph, worn carrier bearings could be the culprit. In some cases, this noise may change in pitch when the vehicle is navigating a turn.

  • Loose pinion-bearing preload. Wolves and dogs aren’t the only things that howl. A car with a loose pinion-bearing preload will often make a howling noise as gears are being changed. In this situation, the howling kicks in only when the vehicle is decelerating. It’s easy to mistake this sound for tire noise.

  • Broken pinion-gear tooth. Does your car frequently make loud clicking or clunking sounds when in motion? This could be caused by a broken pinion-gear tooth.

  • Worn U-joints. If your car excessively shakes or vibrates, worn U-joints could be to blame. In many cases, this vibration becomes more noticeable as the vehicle gathers speed.

  • Bad wheel bearings. Bad wheel bearings can cause your car to make a rumbling sound as it tackles turns.

  • Broken cornering gears. Cornering gears are also known as spider gears. If these gears are broken, you may hear a banging, clicking or clunking sound as your vehicle navigates a corner.

  • Worn transfer case. Your car may have a worn transfer case if it makes a clunking or clicking sound when you press or release the throttle.

  • Out-of-balance driveshaft. An out-of-balance driveshaft may cause your vehicle to vibrate heavily as it accelerates.

  • Worn pinion bearings. If your car makes whirring noises at various speeds, the problem could be caused by worn pinion bearings.

  • Insufficient lubrication. Much like the engine and the transmission, your car’s differential needs proper lubrication to function effectively. The fluid used for this task is known as gear oil or differential oil. If the gear oil is low, it can cause your vehicle to make clunking or banging noises when cornering.

Avoid Serious Consequences With Attentive Repair

Many common problems with differentials can snowball into major headaches if you don’t deal with them in a timely manner.

More importantly, a compromised differential can negatively impact your safety when you’re behind the wheel by making it difficult to turn. A faulty differential can also cause your car’s wheels to lock up, and this can put you in a dangerous situation if it happens while you’re in traffic.

A differential can experience a wide range of problems, but these issues are fairly easy to spot. To prevent things from worsening, promptly repair your vehicle or bring it to a professional if any of the aforementioned parts are damaged or worn.

Check out all the drivetrain parts available on NAPA Online or trust one of our 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on common problems with differentials, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

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