2021 Mercedes-Benz GLA Problems: 1 Issues Every Owner Should Know
2021 model year · 500+ owner reports · Updated April 2026
According to Au7o's analysis of 500+ owner reports, the 2021 Mercedes-Benz GLA has 1 documented known issues. No issues are rated critical, indicating generally reliable ownership. The most commonly reported issue is Transfer Case Noise (AWD Models) with 500 owner reports. Across all issues, repair costs range from $200 to $2,000. DIY maintenance guides at au7o.io.
All 1 Known Issues
On the 2015-2023 Mercedes-Benz GLA, the 4MATIC transfer case on the GLA develops a whining or humming noise at highway speeds. The noise is caused by gear wear inside the power take-off unit that distributes torque to the rear axle. More common on vehicles that have seen off-road use or aggressive driving.
Common Symptoms
- Whining noise at highway speed
- Humming that changes with vehicle speed
How to Fix
Drain and refill the transfer case fluid first — old fluid can cause whining. If noise persists, the power take-off unit needs rebuilding or replacement. Use only Mercedes-approved transfer case fluid.
What Owners Are Using
Parts and tips from 500+ owners who fixed this issue
- TipChange the transfer case fluid every 40,000 miles. Mercedes does not list this as a scheduled service item but it dramatically extends transfer case life.