Suspension arm dust cover at the MOT: which cars fail on it most
1.8% of failed initial MOT tests in 2025 recorded this defect: 168,155 of 9,185,328. By age, it was most common on vehicles 20 years old and over (2.6%) and least common on vehicles 3 to 5 years old (0.2%).
It is one of the 10 most common MOT failures on 19 of the 332 car models we cover. Against vehicles of the same age, it was most common on the Suzuki Baleno, the Vauxhall Mokka and the Kia Stonic. On the Suzuki Baleno, 30.6% of failed tests had it, against 1.6% for all vehicles of the same age.
The DVSA records it as “Suspension arm 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 a suspension arm 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 | Suzuki Baleno1,738 failed tests | 30.6%532 tests | 19.6×all: 1.6% |
| 2 | Vauxhall Mokka77,832 failed tests | 21.8%16,933 tests | 14.1×all: 1.5% |
| 3 | Kia Stonic3,873 failed tests | 4.3%166 tests | 6.9×all: 0.6% |
| 4 | Land Rover Range Rover Sport23,917 failed tests | 9.0%2,157 tests | 5.1×all: 1.8% |
| 5 | Hyundai i2036,388 failed tests | 7.9%2,876 tests | 4.5×all: 1.7% |
| 6 | Jaguar XJ2,924 failed tests | 10.2%298 tests | 4.3×all: 2.4% |
| 7 | Mitsubishi Mirage2,055 failed tests | 6.9%141 tests | 4.1×all: 1.7% |
| 8 | Jaguar S-Type2,495 failed tests | 10.9%273 tests | 4.1×all: 2.6% |
| 9 | Renault Kadjar18,181 failed tests | 5.6%1,026 tests | 3.9×all: 1.4% |
| 10 | Kia Venga13,418 failed tests | 6.7%904 tests | 3.8×all: 1.8% |
| 11 | Jaguar XF23,838 failed tests | 6.7%1,601 tests | 3.5×all: 1.9% |
| 12 | Ford Fusion19,130 failed tests | 8.8%1,690 tests | 3.5×all: 2.5% |
| 13 | Hyundai ix208,692 failed tests | 6.0%525 tests | 3.5×all: 1.7% |
| 14 | Land Rover Range Rover16,887 failed tests | 6.1%1,035 tests | 3.2×all: 1.9% |
| 15 | Kia Rio28,389 failed tests | 5.7%1,605 tests | 3.2×all: 1.8% |
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 20220.2% of failed tests, against 1.8% for all ages1,593 failed tests
- 6 to 9 years, first used 2016 to 20191.5% of failed tests, against 1.8% for all ages31,122 failed tests
- 10 to 14 years, first used 2011 to 20151.8% of failed tests, against 1.8% for all ages59,311 failed tests
- 15 to 19 years, first used 2006 to 20102.5% of failed tests, against 1.8% for all ages54,954 failed tests
- 20 years and over, first used 1985 to 20052.6% of failed tests, against 1.8% for all ages21,148 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 cover2.7% of failed tests
- Anti-roll bar link joint2.3% of failed tests
- Corroded suspension mount1.8% of failed tests
Share of all failed initial MOT tests in 2025.