Anti-roll bar link cover at the MOT: which cars fail on it most
2.7% of failed initial MOT tests in 2025 recorded this defect: 250,906 of 9,185,328. By age, it was most common on vehicles 15 to 19 years old (4.4%) and least common on vehicles 3 to 5 years old (0.5%).
It is one of the 10 most common MOT failures on 54 of the 332 car models we cover. Against vehicles of the same age, it was most common on the Mercedes-Benz GLA, the Vauxhall Viva and the Mercedes-Benz CLA. On the Mercedes-Benz GLA, 8.0% of failed tests had it, against 1.1% for all vehicles of the same age.
The DVSA records it as “Anti-roll bar linkage ball joint dust cover no longer prevents the ingress of dirt”. A failed test can have several defects.
What the MOT checks
The dust cover on an anti-roll bar link ball joint is missing or no longer keeps dirt out.
The MOT inspection manual lists “A suspension joint dust cover missing or no longer prevents the ingress of dirt etc.” as a major defect, so the vehicle fails. “A suspension joint dust cover severely deteriorated” is a minor defect, which doesn't fail the test.
Car models where it is most common
| # | Car | Share of failed tests | Against same age |
|---|---|---|---|
| 1 | Mercedes-Benz GLA15,320 failed tests | 8.0%1,222 tests | 7.0×all: 1.1% |
| 2 | Vauxhall Viva8,150 failed tests | 7.8%632 tests | 5.6×all: 1.4% |
| 3 | Mercedes-Benz CLA14,599 failed tests | 5.3%767 tests | 4.3×all: 1.2% |
| 4 | Toyota Estima2,665 failed tests | 10.8%288 tests | 3.0×all: 3.6% |
| 5 | Mercedes-Benz B-Class19,308 failed tests | 8.9%1,725 tests | 2.8×all: 3.1% |
| 6 | Toyota Verso7,953 failed tests | 8.9%711 tests | 2.8×all: 3.2% |
| 7 | Mercedes-Benz A-Class77,678 failed tests | 5.7%4,399 tests | 2.8×all: 2.0% |
| 8 | Lexus NX2,983 failed tests | 2.8%84 tests | 2.7×all: 1.0% |
| 9 | Volkswagen Touran21,715 failed tests | 9.2%2,006 tests | 2.6×all: 3.5% |
| 10 | Kia Carens3,564 failed tests | 5.1%182 tests | 2.6×all: 2.0% |
| 11 | Volkswagen Sharan6,764 failed tests | 5.2%354 tests | 2.5×all: 2.1% |
| 12 | Skoda Yeti19,347 failed tests | 6.7%1,304 tests | 2.5×all: 2.7% |
| 13 | Toyota iQ4,202 failed tests | 10.0%420 tests | 2.5×all: 4.1% |
| 14 | Citroen C450,643 failed tests | 6.7%3,406 tests | 2.4×all: 2.8% |
| 15 | Volkswagen Eos3,325 failed tests | 10.7%357 tests | 2.4×all: 4.4% |
Only models where this defect is one of their 10 most common MOT failures, with at least 50 failed tests, have a figure. So a model that isn't listed can still have it, just less often than its other faults. Vans, pick-ups and taxis are left out, as in our rankings. × is the model's share divided by the share for all vehicles of the same age.
How common it is by car age
- 3 to 5 years, first used 2020 to 20220.5% of failed tests, against 2.7% for all ages3,736 failed tests
- 6 to 9 years, first used 2016 to 20191.1% of failed tests, against 2.7% for all ages23,076 failed tests
- 10 to 14 years, first used 2011 to 20153.1% of failed tests, against 2.7% for all ages103,638 failed tests
- 15 to 19 years, first used 2006 to 20104.4% of failed tests, against 2.7% for all ages96,894 failed tests
- 20 years and over, first used 1985 to 20052.9% of failed tests, against 2.7% for all ages23,528 failed tests
Not shown, with fewer than 50 failed tests with this defect: vehicles under 3 years old.
All-vehicle figures cover vehicles first used from 1985 to 2024: 9,185,328 of the 9,193,164 failed initial tests in 2025.
How these figures are counted
These are failures recorded at initial MOT tests in 2025. Retests are not counted. A defect found on more than one wheel, lamp or joint at the same test counts once. "Same age" is the defect's share of failed tests for all vehicles first used in the same years, weighted by the model's own failed tests in each year.
An MOT checks safety and emissions on the day of the test. These figures show where a defect was recorded, not why, and not what a repair costs. Figures: DVSA anonymised MOT tests and results, 2025. Contains public sector information licensed under the Open Government Licence v3.0. What the MOT checks: MOT inspection manual: cars and passenger vehicles, GOV.UK, read 1 Nov 2026.
How we choose and rank these defectsOther suspension faults
- Coil spring8.6% of failed tests
- Suspension arm ball joint5.1% of failed tests
- Suspension arm bush4.4% of failed tests
- Shock absorber leak3.1% of failed tests
- Anti-roll bar link joint2.3% of failed tests
- Suspension arm dust cover1.8% of failed tests
- Corroded suspension mount1.8% of failed tests
Share of all failed initial MOT tests in 2025.