When Should U-Joints Be Replaced?

Under normal circumstances, u-joints last a long time. Some even last the lifetime of the vehicle. But sometimes a u-joint can fail unexpectedly. When that happens, you have to replace it ASAP. Neglecting to replace a failed u-joint will likely result in serious issues such as:

• Driveshaft damage
• Transmission failure
• Differential damage or failure
• Unsafe driving conditions

When one of your u-joints fails, you’ll know. You’ll notice some symptoms. It’s important to know what to look for so you can address a failed u-joint before the damage becomes irreparable.

1. Replace Your U-Joints When You Hear A Clunking Sound

When a u-joint fails, it starts making noises. The noise may be constant or intermittent. It’s usually loud enough to hear if you don’t have the radio on.

One common noise that occurs when a u-joint is beginning to fail is a clunking sound. This happens when shifting from forward to reverse or reverse to forward. This means that at least one u-joint is beginning to fail. The good news is that if you replace the u-joint quickly, usually nothing else is damaged.

2. Replace Your U-Joints When You Feel Drivetrain Vibration

The most common problem that causes excessive drivetrain vibration is u-joint failure. When a u-joint fails, the driveshaft can start moving outside of its normal rotation. In other words, it becomes too loose. This causes drivetrain vibration that becomes particularly noticeable at higher speeds. You can sometimes feel this vibration through the floorboards and shift lever.

If your truck or SUV suddenly starts vibrating more than usual, check the u-joints ASAP.

What Happens When You Don’t Replace Your U-Joints

Ignoring these symptoms can result in a u-joint that self-destructs. The driveshaft is then free to bang on the bottom of the vehicle, leading to even more damage. You’ll face some dire consequences if you don’t replace your u-joints ASAP. Most commonly:

• Significant driveshaft damage
• Transmission failure due to a damaged output shaft seal
• Differential failure due to a damaged pinion seal

This post has more information about why it’s very important to replace your u-joints as soon as possible.