October 17, 2017

Road wreckin’: are poor road surfaces and traffic calming damaging cars’ suspensions?

Writeonmotoring  asked a selection of main dealer service departments if they thought poor road surfaces and an increasing use of traffic calming were causing an increase in suspension repairs.

car-suspension

Steve Melvin , Squire Furneaux Volvo

Q: As far as you are aware, has there been an increase in these sorts of repairs on cars over recent years?

A: Parts definitely seem to wear out quicker nowadays, but the problem is quantifying it.

Q: Do you see there being a correlation between an increase in these kind of repairs and an increasing use of traffic calming measures (speed bumps)?

A: Certain models use certain bushes, but then you could say that’s down to motorists driving over speed bumps at 40 mph, which you’re not meant to do. I see numerous examples of people outside the showroom driving over the speed bumps at 40mph  (as if they weren’t there) and you realize that the car has to cope with that.

Q: What are the most common sorts of suspension and tyre problems on cars?

A: We do see lots of bushes on cars requiring replacement. Also more recently there have been lots of six or seven year old V40s coming into the garage with broken coil springs. Alloy wheel damage is also increasingly common on many of the models now coming with 18” low profile wheels. They attribute this damage to potholes. “Instead of it being round, you get a flat spot in the wheel”. That’s if they don’t break entirely. “We have seen wheels that are completely cracked.”

Q: Are newer cars more prone to wheel damage than older cars?

A: Cars used to come with 90 profile tyres. Now many are fitted with 35/45 profile tyres. This means there is very little tyre surrounding the wheel and consequently very little in the way of rubber insulation between the wheel and the road.

Higher profile tyres, as fitted on 4x4s does provide more cushioning of the wheel – especially if hitting a pothole. However, it doesn’t mean that these 4x4s (XC60’s and XC90’s) don’t get damaged, as it is still just a car – and remember that there’s two tone of motor car riding on the suspension system,  so there is more loading on springs, bushes and shock-absorbers.

In a way it’s ironic that the faster the car, the slower they have to go over speed bumps.

Other garages report similar findings.

TrafficCalming

Dean Margetts, Allams  Vauxhall

Dean is of the opinion that the increase in the number of coil spring repairs can be attributed to deteriorating road surfaces and the growing use of traffic calming measures, in the form of speed bumps, or sleeping policeman as they are commonly known. “The most common suspension repairs we deal with are broken coil springs and worn suspension bushes.”

Rob, Service Advisor Thames Honda

The most commons suspension faults are suspension link arms and compliance lower arm bushes, according to Rob, service advisor at Thames Honda.
Rob reckons the increase in suspension repairs are more a result of poor road surfaces and potholes than traffic calming measures. “Thames Honda has a senior customer base, so it’s unlikely our customers would be racing over speed bumps at 40 mph”.

But it’s not just suspension components that are being damaged; tyres too are bearing the brunt of our scarred roads. Rob continues: “ we are seeing more and more damaged tyres with cuts, abrasions and bulges. There is a high likelihood this is attributed to potholes, recessed drain covers and the poor road surface in general.”

Glenn, service advisor, Dagenham Ford

“We see lots of leaking shock absorbers, snapped top mount bearings, lower arm bushes. People drive to quickly over speed bumps – the square ones are ok  as many cars can straddle these – it’s the narrow ones found in car parks that you’ve got to watch out for”.

Typical suspension repair costs:

Vauxhall
Coil Springs: £250 upwards
Suspension bushes: £120 upwards

Honda
Suspension link arms: £70 upwards (per side)
Lower arm bushes: £240 upwards (pair)

Ford
Suspension struts: £300 (pair)
Suspension link arms: £120 (pair)

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