Why Angular Contact Ball Bearings in Gear Reducers Make Noise (And How to Fix It)

Angular contact ball bearings play a key role in the smooth operation of gear reducers. But when they start making noise, it can be a sign of underlying problems.

Understanding the causes of bearing noise helps you prevent breakdowns, improve performance, and extend equipment life. Here are the most common reasons — and how to solve them.

Common Causes of Bearing Noise

1. Too High Speed (RPM)

Running the gear reducer at excessive speeds increases internal friction and vibration, which can lead to abnormal noise.

2. Lubrication Problems

• Not enough grease or oil
• Using the wrong type of lubricant

These issues cause metal-to-metal contact, increasing friction and wear — and often resulting in noise.

3. Incorrect Installation

If bearings are not mounted properly — such as misalignment or incorrect internal clearance — it can create unstable rotation and unusual sounds.

4. Overloading the Bearing

When the load exceeds what the bearing is rated for, it causes extra stress, heat, and vibration, all of which can result in noise.

5. Low-Quality Bearings

Bearings with rough surfaces on the balls or raceways, or those with inconsistent internal tolerances, may produce noise even under normal conditions.

How to Reduce Noise and Improve Bearing Performance

✅ Use the Right Lubrication

• Apply the correct type and amount of grease or oil.
• Follow manufacturer recommendations for lubrication intervals.

✅ Install Bearings Correctly

• Always follow proper installation methods.
• Check alignment and internal clearance during setup.

✅ Control Operating Speed

• Avoid running the gear reducer beyond its recommended RPM range.

✅ Monitor Load Levels

• Ensure loads stay within the bearing’s capacity.
• Regularly inspect operating conditions to avoid overloading.

✅ Choose High-Quality Bearings

• Invest in precision-engineered angular contact ball bearings from trusted manufacturers.
• Quality bearings reduce noise, last longer, and perform better under pressure.

Final Thoughts

Noise from angular contact ball bearings doesn’t always mean failure — but it’s a warning sign that shouldn’t be ignored. Most bearing noise is preventable by addressing:

• Lubrication
• Installation
• Load
• Speed

and using high-quality components.

By taking care of these factors, you’ll keep your gear reducers running quieter, smoother, and more efficiently.

Looking for Quiet, Durable Bearings?

At Beining Technology, we design high-precision angular contact ball bearings specifically for demanding gear reducer applications. Built for reliability, performance, and long service life.