MOT advisory explained
“Anti-roll bar pin or bush worn”
The rubber blocks that clamp the anti-roll bar to the body have gone soft, split or worn oval. Testers call them D bushes, and they write that name on this advisory a quarter of a million times. It is one of the cheapest suspension parts on the car, and on some vans it is close to an annual event.
The anti-roll bar is a sprung steel bar across the car that resists body lean in corners. It is held to the body by two rubber bushes shaped like a letter D, clamped in steel brackets. The tester found one of those bushes worn, so the bar can move in its mount, but not enough to fail.
Only 4.5% fail on the anti-roll bar itself at the next test. But 16.0% fail on some suspension pin, bush or joint, and that gap matters: worn D bushes are a sign of an underside where all the rubber is the same age.
Two different parts share the words anti-roll bar on a certificate. This page is the mounting bushes on the bar. The short links at each end have their own advisories: linkage pin or bush worn and linkage ball joint has slight play. The tester’s note usually says which.
An “anti-roll bar pin or bush worn but not resulting in excessive movement” advisory means the rubber D bushes clamping the anti-roll bar to the body are worn, so the bar moves slightly in its mounts, but not enough to fail. According to DVSA MOT data analysed by PriceMyRepair, 4.5% of 1.3 million such advisories failed on the anti-roll bar at the next test, and 16.0% on any suspension pin, bush or joint.
What a D bush is
A rubber saddle. The bar passes through a rubber block, flat on one side and round on the other, hence the name, and a steel bracket bolts over it to the body or subframe. The rubber lets the bar twist freely while holding it in place. Two per bar, so four on a car with bars at both ends. “d bush” is the most common note on this advisory, at 252,888, and the next eleven are mostly variations.
How it wears. The rubber goes hard with age and heat, then splits. Oil or grease softens it. Either way the bar ends up loose in the bracket, knocking against the steel on every bump. The knock is the symptom: a hollow clonk from under the front over small bumps, usually at low speed.
The second wording. One in three of these is written as “anti-roll bar ball joint has slight play”, the second wording on this page. It shares the code and describes a similar fault at the bar’s ends on cars where the link is part of the bar. The numbers are the same.
Will it fail next year?
Two wordings share this page, both under the same defect code. Together they have been recorded 3,485,175 times, and 1,324,400 can be followed to the same vehicle’s next MOT.
| What happened at the next test | Share |
|---|---|
| Failed on the same component | 4.5% |
| Failed on anything under defect 5.3.4 | 16.0% |
| Same advisory recorded again | 13.8% |
According to DVSA MOT data analysed by PriceMyRepair: 1,324,400 advisories followed to the same vehicle’s next test. Rows can overlap.
The two failure rows are far apart and the gap is the story. The bar itself fails 4.5% of the time, because a D bush rarely gets bad enough to let the bar move excessively and it is cheap enough that many are replaced. But 16.0% of these cars fail on a suspension pin, bush or joint of some kind, which is nearly as high as after a suspension arm ball joint advisory at 20.6%.
A D bush is the first rubber to show its age because it is the softest and most exposed. When it has gone, the arm bushes and drop links on the same car are close behind.
| 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 |
| Anti-roll bar linkage ball joint has slight play | 10.0% | 17.8% | 17.1% | 2,098,185 |
| 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 linkage pin or bush worn | 4.8% | 11.9% | 23.0% | 826,670 |
| Anti-roll bar pin or bush worn | 4.5% | 16.0% | 13.8% | 1,324,400 |
Rubber ages, so the advisory climbs from 1.1 per 1,000 tests at 3–4 years to 17.5 in the late teens. The share that fail on the bar itself barely moves, staying between four and five in a hundred. What rises with age is everything else on the underside.
| Age of car | Per 1,000 tests | Fails on same part | Followed |
|---|---|---|---|
| 3–4 years | 1.1 | 3.9% | 32,269 |
| 5–6 years | 2.4 | 4.3% | 72,648 |
| 7–9 years | 5.0 | 4.3% | 206,961 |
| 10–12 years | 9.4 | 4.5% | 320,284 |
| 13–15 years | 14.1 | 4.8% | 332,962 |
| 16–19 years | 17.7 | 4.7% | 254,303 |
| 20 years and over | 17.5 | 3.9% | 92,136 |
Replacing D bushes takes a few minutes per side once the car is up: two bolts, bracket off, old bush off, new bush on. The useful part of the visit is the five minutes after, with a lever bar on the arm bushes and drop links on the same axle.
If those are sound, the D bushes were an early warning and nothing more. If they have play too, you have found the 16.0% before the tester does.
On some 4x4s and vans the D bush brackets bolt to a subframe that corrodes around the bolts. Seized or sheared bolts turn a ten-minute job into an hour. Ask for a price that allows for it.
Exact wording on your certificate
Two advisories under one code, one for the bushes and one for a ball joint at the bar. The failure is movement the tester judges excessive.
| Line on the certificate | Result | Code |
|---|---|---|
| Anti-roll bar pin or bush worn but not resulting in excessive movement | Advisory — pass | 5.3.4 (a) (i) |
| Anti-roll bar ball joint has slight play | Advisory — pass | 5.3.4 (a) (i) |
| Anti-roll bar pin or bush excessively worn | Major — fail | 5.3.4 (a) (i) |
The two front corners lead, but the rear is not far behind, at nearly four in ten. Many larger cars and most 4x4s have a rear anti-roll bar with its own D bushes, sitting in the spray from the front wheels.
| Position written by the tester | Share of all instances |
|---|---|
| Nearside front | 18% |
| Offside front | 16% |
| Front | 14% |
| Nearside rear | 13% |
| Offside rear | 12% |
| Rear | 11% |
From 3,485,175 recorded instances. Testers can add their own note after the standard wording. The most common on this advisory: “d bush” (252,888), “d bushes” (66,428), “both” (60,405), “both sides” (50,471), “d-bush” (37,204), “both d bushes” (25,688), “'d' bush” (18,549), “both front” (11,370).
What it costs
A pair of D bushes is one of the cheapest suspension parts on any car and the labour is short on most. We do not hold a canonical price for it, so we do not publish a range. Ask for a price for the pair, fitted, and ask whether the drop links should be done at the same time, since the bar is already unbolted. Related prices are on the suspension repair cost page.
Can I still drive with this advisory?
You may hear a clonk over small bumps and feel a little more body roll in corners. Neither is urgent. Have the bushes changed at the next service, and use the visit to have the rest of the suspension rubber checked.
Enter your reg to see every suspension advisory your car has had. D bushes one year and an arm bush the next is the pattern the numbers predict.
Which cars get this advisory most?
The all-vehicle rate is 4.8 per 1,000 tests. On the models below it is four to eleven times that.
| Model | Per 1,000 tests | Vs all cars | Tests |
|---|---|---|---|
| Volkswagen Caddy | 51 | 10.7× | 1,459,681 |
| Isuzu D-Max | 43 | 9.1× | 323,076 |
| Mercedes-Benz Sprinter | 38 | 8.0× | 2,101,182 |
| Mitsubishi Shogun | 37 | 7.7× | 420,039 |
| Volkswagen Amarok | 33 | 6.9× | 183,218 |
| Nissan X-Trail | 32 | 6.8× | 928,646 |
| Mitsubishi L200 | 28 | 5.8× | 935,407 |
| Volvo V70 | 22 | 4.6× | 542,743 |
| Nissan Navara | 21 | 4.5× | 712,261 |
| Volkswagen Transporter | 21 | 4.4× | 3,128,645 |
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.
The Volkswagen Caddy leads at 10.7 times the average, and the rest is pickups and 4x4s: the Isuzu D-Max, Mitsubishi Shogun, Volkswagen Amarok, Nissan X-Trail, Mitsubishi L200 and Nissan Navara. Heavy vehicles put more load through their anti-roll bars, and many of these run rear bars as well as front ones, doubling the number of bushes that can wear.
The Mercedes-Benz Sprinter and Volkswagen Transporter are the vans that appear on nearly every suspension list, for the same reasons.
What to do next
- Confirm it is the D bushes. The tester’s note usually says. If it says link, you are on the wrong page.
- Do the pair. Both bushes on that bar. They are the same age and the second one is a few bolts away.
- Have the arm bushes and drop links levered while it is up. That is where the 16.0% comes from, and the check takes minutes.
- Ask about seized bolts before agreeing a price. On older 4x4s the brackets can be the hard part.
Anti-roll bar D bush advisory FAQ
What does anti-roll bar pin or bush worn mean on an MOT?
The rubber bushes that clamp the anti-roll bar to the body, known as D bushes, are worn, so the bar can move slightly in its mounts. It has not reached excessive movement, so it is an advisory and the car passes.
What is a D bush?
A D-shaped rubber block that the anti-roll bar passes through, held to the body by a steel bracket. There are two per bar. It lets the bar twist while holding it in place, and it is the single most common note testers write on this advisory.
Will it fail the next MOT?
According to DVSA MOT data analysed by PriceMyRepair, 4.5% of 1.3 million such advisories failed on the anti-roll bar at the next test, but 16.0% failed on some suspension pin, bush or joint. Worn D bushes usually mean the rest of the suspension rubber is the same age.
What does a worn anti-roll bar bush sound like?
A hollow clonk from under the car over small bumps at low speed, as the bar knocks in its bracket. The car may also lean a little more in corners.
How much does it cost to replace anti-roll bar bushes?
The bushes are inexpensive and the labour is short on most cars. We do not publish a range for this job. Ask for the pair fitted, and allow for seized bracket bolts on older 4x4s. Any prices on this site are estimates and final quotes come from garages.
Which vehicles get this advisory most?
The Volkswagen Caddy, at 10.7 times the average rate, and pickups and 4x4s such as the Isuzu D-Max, Mitsubishi Shogun and Volkswagen Amarok.
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 3,485,175 times; 1,324,400 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.