How does the inner CV joint make noise?

Anna Tkach

AutoPortal editorial team

1,973 views 3 min read

Inner CV joint is an important element of the transmission of a front-wheel drive car. It is responsible for transmitting torque from the gearbox to the wheels and operates under constant load. Over time, this unit can wear out, and one of the first signs of malfunction is a foreign sound. But how to determine how the inner CV joint makes noise and distinguish this noise from other possible malfunctions? In this material, we will analyze characteristic sounds, causes of failure, and diagnostic methods.

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What is an inner CV joint

A CV joint is a constant velocity joint. It ensures smooth and uniform transmission of torque even when the drive angle changes. Front-wheel drive cars use two types: outer (closer to the wheel) and inner (on the gearbox side). The inner CV joint works in constant conjunction with the gearbox, so it experiences significant loads, especially when starting from a standstill, hard acceleration, or towing.

How does the inner CV joint make noise

If you are wondering how the inner CV joint makes noise, pay attention to the following signs:

A dull thud during acceleration, especially in first and second gear.
Clicks or impacts when the clutch is released abruptly.
Knocking when shifting from reverse to forward gear.
Vibrations while driving at speed, most often starting from 40-60 km/h.
Unusual noises in the gearbox area when driving straight.

The difference of the inner CV joint is that it makes noise when driving straight, not when turning, unlike the outer one. This helps to identify the source of the sound more accurately.

Causes of noise

Knowing how the CV joint makes noise, you can assume the cause of the malfunction. The main factors:

Mechanical wear of the balls and grooves inside the joint.
Loss of lubricant due to a damaged boot.
Moisture and dirt getting inside the CV joint.
Loosening of the drive fastening or play in the connections.
Imbalance after installing cheap or defective parts.

How to distinguish the noise of the inner CV joint from other problems

Often the noise of the CV joint is confused with a malfunction of the suspension or gearbox. To avoid mistakes, you can perform a simple check:

If knocking occurs only when turning, this is a sign of a faulty outer CV joint.
If sounds occur during acceleration and when driving straight, it is likely the inner one making noise.
When rocking the wheel back and forth with the car lifted, there may be play in the drive - this can also indicate a problem with the inner CV joint.

What to do if the inner CV joint is noisy

If you have accurately determined how the inner CV joint makes noise and are sure of the cause of the malfunction, further actions depend on the degree of wear:

Replace the boot and add lubricant if the damage is minor.
Install a repair kit (balls, cage) with moderate wear.
Perform a complete replacement of the CV joint in case of significant play or wear of the working surfaces.

It is important to use high-quality components and lubricants recommended by the manufacturer.

Knowing how the inner CV joint makes noise helps to identify the problem in time and avoid more serious damage to the transmission. Listen to the sounds of your car, especially when starting and shifting gears. If you notice unusual knocking, vibrations, or jerks, it is worth getting a diagnostic. The sooner you fix the problem, the lower the repair costs and the higher the driving safety.