MOT advisory explained
“Shock absorbers has a slightly worn bush”
The damper itself is usually fine. What has worn is the rubber it is mounted in, and on a few vehicles that rubber is a routine service item. Here is how to tell which case is yours.
Each shock absorber is fixed to the car through rubber: a bush in the eye at the bottom, and a bush or a top mount at the upper end. The tester found one of them slightly worn. The shock still damps and is still secure, so it is a pass.
8.9% of these fail on the same shock absorber at the next test, which is higher than the better-known oil misting advisory. A worn bush lets the shock knock against its mounting, and that knocking finishes the bush off.
Fitted, independent garage. That is the full-price outcome. Where the bush or top mount is sold on its own the bill is much lower, so ask before agreeing to new shocks.
This is a different advisory from “light misting of oil”. Misting is about the damper leaking. This one is about how it is attached. You can have either without the other.
A “shock absorbers has a slightly worn bush” advisory means the rubber bush or top mount holding a shock absorber to the car has slight wear, while the shock itself still works and is secure, so the car passes. If the shocks have to be replaced, a pair costs £150–£360 per axle at an independent garage. According to DVSA MOT data analysed by PriceMyRepair, 8.9% of 607,181 such advisories followed to the next test failed on the same shock absorber.
The rubber, not the damper
Three places it can be. A conventional shock has a rubber bush pressed into a steel eye at the bottom and a bush or stacked rubber washers at the top. A strut has a top mount, a rubber and metal bearing under the bonnet or in the rear arch. Any of the three can be what the tester saw.
What testers write. The most common note added to this advisory is “top mount”, 48,257 times, ahead of “lower bush” and “top bush”. So a large share of these are top mounts, which are a separate part from the shock and can be changed without it.
What you notice. A dull knock from one corner over broken surfaces, often worse when cold. The ride itself does not change, because the damper is still doing its work. That is how you tell this apart from a tired shock, which makes the car float and bounce.
Will it fail next year?
We followed 607,181 of these advisories to the same vehicle’s next MOT, out of 1,667,672 recorded.
| What happened at the next test | Share |
|---|---|
| Failed on the same component | 8.9% |
| Same advisory recorded again | 19.9% |
According to DVSA MOT data analysed by PriceMyRepair: 607,181 advisories followed to the same vehicle’s next test. Rows can overlap.
For a part made of rubber that is a high figure. A worn suspension arm bush fails 7.4% of the time and light misting on the same shock absorber 7.9%. The difference is load. A shock bush is small and takes a hammer blow on every bump, so once it has play it does not last.
About one in five is written down again unchanged a year later. The rest were fixed, or the car left the record.
| Advisory wording | Fails on same part | Advised again | Followed |
|---|---|---|---|
| Anti-roll bar linkage ball joint has slight play | 10.0% | 17.1% | 2,098,185 |
| Shock absorbers has a slightly worn bush | 8.9% | 19.9% | 607,181 |
| Shock absorbers has light misting of oil | 7.9% | 26.2% | 5,360,491 |
| Suspension arm pin or bush worn | 7.4% | 29.3% | 8,344,577 |
| Shock absorbers has a reduced damping effect | 6.8% | 13.8% | 252,845 |
| Coil spring corroded | 5.0% | 39.1% | 4,780,118 |
| Shock absorbers has slight external damage to the casing | 4.3% | 23.2% | 452,485 |
The age figures hold a surprise. The advisory is most common on the oldest vehicles, 10.5 per 1,000 tests at 20 years and over, yet that is where it is least likely to become a failure, at 6.2%. The peak is 11.5%, at 7–9 years.
| Age of car | Per 1,000 tests | Fails on same part | Followed |
|---|---|---|---|
| 3–4 years | 0.9 | 8.6% | 27,810 |
| 5–6 years | 1.7 | 10.7% | 53,924 |
| 7–9 years | 2.9 | 11.5% | 121,421 |
| 10–12 years | 3.9 | 10.1% | 127,216 |
| 13–15 years | 4.8 | 7.8% | 110,208 |
| 16–19 years | 6.4 | 6.2% | 90,824 |
| 20 years and over | 10.5 | 6.2% | 59,927 |
Many of the older vehicles with this advisory are 4x4s and pickups whose shock bushes are a cheap, separate part. Owners and garages swap them as routine, so the advisory rarely matures into a fail.
On a seven to nine year old car the shock is more often a sealed unit with the bush bonded in. Nobody replaces a whole shock for a slight knock, so it gets left, and it is these that come back as failures.
If yours is the sealed kind, the honest choice is between living with the knock until the next MOT and paying for a pair of shocks now. It will not get better.
Exact wording on your certificate
The grammar is DVSA’s own, “shock absorbers has”, and it appears that way on every certificate. The failure version keeps the same code and changes one word.
| Line on the certificate | Result | Code |
|---|---|---|
| Shock absorbers has a slightly worn bush | Advisory — pass | 5.3.2 (c) |
| Shock absorber has a slightly worn bush | Advisory — pass | 5.3.2 (c) |
| Shock absorber has an excessively worn bush | Major — fail | 5.3.2 (c) |
This is mainly a rear axle advisory, and where the tester gives more detail it is usually the upper mounting. Rear shocks on most cars are separate from the spring and rely on small bushes at both ends.
| Position written by the tester | Share of all instances |
|---|---|
| Nearside rear | 14% |
| Offside rear | 14% |
| Nearside rear upper | 8% |
| Offside rear upper | 8% |
| Nearside front | 7% |
| Offside front | 7% |
From 1,667,672 recorded instances. Testers can add their own note after the standard wording. The most common on this advisory: “top mount” (48,257), “both” (35,357), “both sides” (30,718), “lower bush” (12,131), “top bush” (11,775), “upper bush” (9,530), “both rear” (7,640), “top mounting” (5,501).
What it costs, from cheapest outcome to dearest
| Job | Price fitted | Notes |
|---|---|---|
| Top mounts, fitted | £40–£90 | When the worn part is the strut top mount |
| Pair of shock absorbers, one axle | £150–£360 | When the bush is bonded into the shock |
| Alignment afterwards | £40–£60 | Front struts only. Not needed for rear shocks |
Fitted at an independent garage. On vehicles with separate shock bushes, mostly 4x4s and pickups, a bush kit costs less than any row above. Shocks are always replaced as an axle pair. Prices by model are on the shock absorber replacement cost page.
Can I still drive with this advisory?
Expect a knock that slowly gets louder. If it turns into a heavy clunk, or the car starts to feel unsettled over bumps on that corner, the bush has probably failed completely and the shock is moving on its mounting. Get it looked at then and do not wait for the test.
Enter your reg to see your car’s whole MOT record. If the same corner has been advised before, it will show, and we will price the job for your model.
Which cars get this advisory most?
Across every vehicle tested, this advisory appears on 3.4 of each 1,000 tests. The models below are in a different league.
| Model | Per 1,000 tests | Vs all cars | Tests |
|---|---|---|---|
| Land Rover Defender | 62 | 18.3× | 1,232,451 |
| Isuzu D-Max | 55 | 16.2× | 323,076 |
| Fiat Panda | 45 | 13.4× | 1,004,369 |
| Fiat 500 | 42 | 12.5× | 3,224,134 |
| Fiat Doblo | 27 | 7.9× | 537,931 |
| Ford Ka | 22 | 6.5× | 2,120,213 |
| Mitsubishi L200 | 19 | 5.5× | 935,407 |
| Volkswagen Crafter | 17 | 5.0× | 585,956 |
| Mercedes-Benz Sprinter | 17 | 4.9× | 2,101,182 |
| Fiat Punto | 11 | 3.3× | 1,031,944 |
Model families are grouped by the first word of the DVSA model name, so “Transit” covers every Transit variant. Only models with at least 60,000 tests are ranked.
Two families account for most of the list. The first is ladder-frame 4x4s and pickups: the Land Rover Defender at 18.3 times the average, the Isuzu D-Max and the Mitsubishi L200. Their shocks are mounted on simple rubber bushes that are meant to be replaced, and they wear quickly off-road.
The second is small Fiats. The Fiat Panda, Fiat 500 and Fiat Punto are all here, and so is the Ford Ka, which in its later form was built on the Fiat 500’s platform. On these the advisory is 12.5 to 13.4 times as common as on an average car.
What to do next
- Find out which end. Top mount, upper bush or lower bush. It decides whether this is a small job or a pair of shocks.
- Ask what is sold separately. On a Defender the bushes are pocket money. On most hatchbacks the lower bush comes with the shock. Your garage’s parts supplier can answer in a minute.
- Do the axle, not the corner. If it does come to new shocks, both sides of that axle are changed together. One new shock beside one old one upsets the handling.
- Rule out the cheap suspect. A knock from the front is more often an anti-roll bar link than a shock bush. Have that checked before spending on shocks.
Shock absorber worn bush advisory FAQ
What does shock absorbers has a slightly worn bush mean?
The rubber bush or top mount that fixes a shock absorber to the car has slight wear. The shock absorber itself still works and is secure, so it is recorded as an advisory and the car passes.
Will a worn shock absorber bush fail the next MOT?
It can. According to DVSA MOT data analysed by PriceMyRepair, 8.9% of 607,181 such advisories failed on the same shock absorber at the next test, more than the 7.9% seen after an oil misting advisory.
Can the bush be replaced without replacing the shock absorber?
Sometimes. Strut top mounts are always a separate part. On many 4x4s and pickups the shock bushes are separate too. On most ordinary cars the lower bush is bonded into the shock and the two are replaced together.
How much does it cost to fix a worn shock absorber bush?
Top mounts cost £40–£90 fitted. If the bush is part of the shock, a pair of shock absorbers costs £150–£360 per axle at an independent garage. These are estimates and final quotes come from garages.
Is it safe to drive with a worn shock absorber bush?
Yes, at the advisory stage. The shock is still secure. If the knock becomes a heavy clunk or that corner feels unsettled, have it checked without waiting for the next MOT.
Which cars get this advisory most?
The Land Rover Defender and Isuzu D-Max, at 18.3 and 16.2 times the average, then the Fiat Panda and Fiat 500. 4x4s, pickups, large vans and small Fiats make up the whole top ten.
How these figures were calculated. According to DVSA MOT data analysed by PriceMyRepair, from the DVSA anonymised MOT test results (Open Government Licence v3.0): 350,943,111 tests. This advisory was recorded 1,667,672 times; 607,181 of those were followed to the same vehicle’s next test between 180 and 730 days later. “Fails on the same part” means a failure at that next test under the same defect code and naming the same component, on either side of the vehicle. Testers do not always name a component the same way twice, so the figure is a floor. Method and how to cite.