MOT advisory explained
“MacPherson strut pin or bush worn”
The rubber and bearing at the top of a front strut, under the bonnet, has worn. Testers write “top mount” on this advisory nearly two hundred thousand times. It knocks over bumps, it can make the steering creak, and on three small Vauxhalls it is close to a service item.
A MacPherson strut is the tall unit behind each front wheel that combines the damper and spring. At its top it bolts to the inner wing through a rubber mount with a bearing in it, so the whole strut can turn when you steer. The tester found play or wear in that mount, or in the bush at the strut’s base.
Only 2.0% fail on the strut itself at the next test. But 11.8% fail on some suspension pin, bush or joint, six times as many. A worn top mount is rarely the thing that fails the car. It is the thing that tells you the rest is due.
Both sides, added to a shock absorber job. Done on their own the strut still has to come out, so the labour is nearly the same as for new struts.
If your certificate also mentions “shock absorbers has a slightly worn bush” or misting, do the mounts and the struts together. The strut has to come out for either, and paying that labour twice is the expensive way to do it.
A “MacPherson strut pin or bush worn but not resulting in excessive movement” advisory means the rubber mounting at the top of a front strut, or the bush at its base, has wear within limits, so the car passes. It is nearly always the top mount. New top mounts cost £40–£90 fitted. According to DVSA MOT data analysed by PriceMyRepair, 2.0% of 562,037 such advisories failed on the strut at the next test, and 11.8% on any suspension joint.
What a top mount does
Rubber and a bearing. The top mount carries the weight of that corner of the car into the body through a block of rubber, and it contains a bearing so the strut can rotate as the wheel steers. The rubber perishes and sags; the bearing dries out and goes rough. “top mount” is the most common note, at 182,326, with “top mounting”, “top strut mount” and “top mount bush” behind it.
What you notice. A knock from the top of the strut over bumps, often heard through the bulkhead more than felt. A creak or graunch when turning the wheel at low speed, which is the bearing. A strut that appears to sit lower on one side. Sometimes the steering does not self-centre as cleanly after a turn.
The lower bush. The second wording on this page is the strut’s lower ball joint, on cars where the strut carries one. It is rare, at fewer than one in twenty of these, and its numbers are similar. Most of what this page describes is the mount under the bonnet.
Will it fail next year?
Two wordings under one code, recorded 1,489,615 times between them, with 562,037 followed to the same vehicle’s next MOT.
| What happened at the next test | Share |
|---|---|
| Failed on the same component | 2.0% |
| Failed on anything under defect 5.3.4 | 11.8% |
| Same advisory recorded again | 19.5% |
According to DVSA MOT data analysed by PriceMyRepair: 562,037 advisories followed to the same vehicle’s next test. Rows can overlap.
The strut itself almost never fails. A top mount has to be badly gone before the movement is excessive, and many are replaced with the shocks before that. What the second row shows is company: 11.8% of these cars fail on some suspension joint, close to the 13.5% after a worn arm bush.
The top mount is another piece of rubber that ages with the rest. When it has gone, the arm bushes, drop links and D bushes on the same car have had the same years.
| Advisory wording | Fails on same part | Fails under same code | Advised again | Followed |
|---|---|---|---|---|
| Suspension arm ball joint has slight play | 16.0% | 20.6% | 17.3% | 2,285,155 |
| Shock absorbers has a slightly worn bush | 8.9% | 8.9% | 19.9% | 607,181 |
| Suspension arm pin or bush worn | 7.4% | 13.5% | 29.3% | 8,344,577 |
| Coil spring corroded | 5.0% | 5.0% | 39.1% | 4,780,118 |
| Anti-roll bar pin or bush worn | 4.5% | 16.0% | 13.8% | 1,324,400 |
| Macpherson strut pin or bush worn | 2.0% | 11.8% | 19.5% | 562,037 |
| Macpherson strut corroded | 1.6% | 3.3% | 22.5% | 370,013 |
The advisory rises from 0.6 per 1,000 tests at 3–4 years to 5.8 in the late teens, and the share that fail on the strut itself barely moves, from 1.2% to 2.3%. Rubber ages at the same rate whatever the car’s birthday.
| Age of car | Per 1,000 tests | Fails on same part | Followed |
|---|---|---|---|
| 3–4 years | 0.6 | 1.2% | 20,066 |
| 5–6 years | 1.5 | 1.4% | 47,361 |
| 7–9 years | 2.8 | 1.8% | 115,401 |
| 10–12 years | 4.3 | 2.0% | 137,259 |
| 13–15 years | 5.4 | 2.1% | 120,089 |
| 16–19 years | 6.8 | 2.3% | 89,676 |
| 20 years and over | 5.8 | 2.3% | 27,951 |
Replacing a top mount means removing the strut, compressing the spring, taking the mount off the top and putting it all back. That is the same work as fitting a new strut, minus the strut. So the sensible question is not whether to replace the mounts but whether the struts should go at the same time.
On a car over ten years old on its original dampers, the answer is usually yes. On a car with newer struts, mounts alone make sense.
Spring compressors are the most dangerous tool in a workshop. This is not a driveway job unless you have the right kit and know exactly what you are doing.
Exact wording on your certificate
Two advisories under the same code, one for the mount or bush and one for a ball joint at the strut. The failure is excessive movement.
| Line on the certificate | Result | Code |
|---|---|---|
| Macpherson strut pin or bush worn but not resulting in excessive movement | Advisory — pass | 5.3.4 (a) (i) |
| Macpherson strut ball joint has slight play | Advisory — pass | 5.3.4 (a) (i) |
| MacPherson strut pin or bush excessively worn | Major — fail | 5.3.4 (a) (i) |
“offside front upper” and “nearside front upper” lead, and every common position is at the front. Struts are a front suspension design on nearly all cars, and the word upper is the top mount.
| Position written by the tester | Share of all instances |
|---|---|
| Offside front upper | 23% |
| Nearside front upper | 23% |
| Offside front | 19% |
| Nearside front | 19% |
| Front | 6% |
| Front upper | 5% |
From 1,489,615 recorded instances. Testers can add their own note after the standard wording. The most common on this advisory: “top mount” (182,326), “both sides” (30,394), “both” (26,635), “top mounting” (13,673), “both front” (6,224), “both side” (6,185), “top strut mount” (6,093), “strut top mount” (5,836).
What it costs
| Job | Price fitted | Notes |
|---|---|---|
| Top mounts, both sides, added to a strut job | £40–£90 | The efficient way |
| Pair of front struts | £160–£520 | If the dampers are due as well |
| Alignment afterwards | £40–£60 | Needed after the struts come out |
Independent garage prices, parts and labour. Top mounts on their own cost more than the table suggests, because the strut still has to come out. Prices by model are on the shock absorber replacement cost page.
Can I still drive with this advisory?
A knock over bumps and a creak on full lock are the signs it is getting worse. Plan the mounts within a few months, and with the struts if those are original.
Enter your reg for your car’s full MOT record. A top mount advisory beside a shock absorber advisory is one visit to the garage, not two.
Which cars get this advisory most?
The all-vehicle rate is 3.2 per 1,000 tests. On the models below it is four to eight times that.
| Model | Per 1,000 tests | Vs all cars | Tests |
|---|---|---|---|
| Vauxhall Adam | 26 | 8.3× | 554,140 |
| Vauxhall Agila | 25 | 8.0× | 435,853 |
| Vauxhall Corsa | 23 | 7.3× | 10,416,613 |
| Honda Jazz | 19 | 6.0× | 3,292,357 |
| Fiat 500 | 18 | 5.8× | 3,224,134 |
| Ford Ka | 18 | 5.8× | 2,120,213 |
| Volkswagen Sharan | 17 | 5.4× | 371,496 |
| Vauxhall Mokka | 16 | 5.2× | 2,042,704 |
| Volkswagen Beetle | 16 | 5.1× | 586,588 |
| Vauxhall Vivaro | 14 | 4.3× | 2,438,602 |
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.
Three small Vauxhalls lead: the Vauxhall Adam at 8.3 times the average, the Vauxhall Agila and the Vauxhall Corsa, the last on more than ten million tests. The Vauxhall Mokka and Vauxhall Vivaro are Vauxhalls too. Their top mount is a known wear item and a routine job in any garage.
The Honda Jazz, Fiat 500 and Ford Ka are the other small cars, and the Fiat 500 and Ford Ka share a platform.
What to do next
- Listen on full lock. Turn the wheel from side to side with the car stationary. A creak or a click from under the bonnet is the bearing.
- Ask about the struts. If they are original and the car is past ten years, do both together.
- Do both sides. They are the same age and the second one costs little more once the first is out.
- Have the alignment checked. Removing a strut disturbs it, and a new mount can change the ride height slightly.
MacPherson strut mount advisory FAQ
What does MacPherson strut pin or bush worn mean on an MOT?
The rubber mounting at the top of a front strut, or the bush at its base, has wear that is still within limits. Testers’ notes show it is nearly always the top mount. It is an advisory and the car passes.
What are the symptoms of a worn strut top mount?
A knock from the top of the strut over bumps, a creak or clicking when turning the steering at low speed, and sometimes steering that does not self-centre cleanly.
Will a worn top mount fail the next MOT?
According to DVSA MOT data analysed by PriceMyRepair, 2.0% of 562,037 such advisories failed on the strut at the next test, but 11.8% failed on some suspension pin, bush or joint. A worn mount is a sign the rest of the suspension rubber is the same age.
How much do strut top mounts cost to replace?
£40–£90 fitted for the pair when done with new struts. On their own the labour is nearly the same because the strut still has to come out. A pair of front struts costs £160–£520. These are estimates and final quotes come from garages.
Should I replace the struts at the same time?
Usually, if they are original and the car is over ten years old. The strut has to come out for the mount either way, so doing both saves a second labour charge.
Which cars get this advisory most?
The Vauxhall Adam, Vauxhall Agila and Vauxhall Corsa, at seven to eight times the average rate, followed by the Honda Jazz, Fiat 500 and Ford Ka.
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 1,489,615 times; 562,037 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.