Archive for the ‘suspension’ Category

Dangerous to drive

It is not often that I feel the need to highlight something on the VT30 failure notice as being dangerous to drive, just recently I have had to use it for brakes and suspension faults. The first case being a pair of rear  leaf springs on a Ford Transit which had fractured at the anchor end spring eye, the only thing holding the spring in place being the weight of the vehicle bearing on the spring eye.


The spring can clearly be seen, from the rust “witness marks” to have worn away at the anchor bracket where it has been moving sideways.

leafspringAnother pair of items to crop up under the dangerous to drive tag was a a pair of front brake hoses on a Ford Maverick these had deteriorated so badly that the braided innards of the hoses were clearly visible













Earlier in the day a customer had brought us a Mercedes ML320 with a pad warning light on, and asked us to replace the front brake pads as he’d done the rears, or friend had, to save some cash.  Once we’d removed the wheels to replace the front pads we knew they were not the reason for the warning light being illuminated, so we turned to the rears to check the wear sensor wire, immediately noticeable was  the thread of a brake caliper bolt and therefore the lower end of the caliper was not secured and had broken the sensor wire, thus causing the light to come on.


Had this been the upper caliper bolt it is quite possible that if the caliper had been caught by the wheel rim it would have caused serious damage to the wheel, the caliper and the caliper bracket, with the wheel quite possibly locking up .


Incidents like these are rare but unfortunately they do happen, which is why we have Mot’s, no matter how a good a mechanic you are, or think you are, another pair of eyes checking the work afterwards can be an extra safeguard for vehicles on our busy roads.


Dangerous tyres once again.

I’m often amazed at the lack of awareness of some drivers.  A Peugeot 307  brought in for mot had an obviously noisy exhaust blow,  the vehicle presenter was surprised when the boss said it was unlikely to pass the test with it blowing as it was.  However we  proceeded to carry out the Mot, before it had even been logged onto the system it was obviously going to be one of those vehicles, just a quick glance before getting into the drivers seat and it was labelled as dangerous to drive.
delaminated-tyre It started poorly and then went from bad to worse, as a glance at the 2 page vt30 shows

The front suspension arm bushes very badly worn and knocking, a rear brake binding, front brakes pulling severely to the right (into the path of oncoming traffic). Never before have I had to issue a VT30 with more than a couple of “dangerous to drive”   items.  Just manoeuvring the vehicle on our forecourt was enough to frighten me, clunking from the suspension, dragging from a rear wheel and then seeing the presence of a child seat in the car was a little worrying too.

Bushes, suspension and steering

Rubber bushes are used nowadays on the majority of vehicles to isolate and dampen road noise whilst at the same time allowing suspension and steering components some flexibility and movement.

Problems begin when the bushes deteriorate or become unbonded, when this happens the suspension component is no longer retained in its correct position, excessive movement occurs and noise increases.

The above are all examples from the front suspension, the rear suspension can also have rubber bushes and mountings, again when the bush deteriorates excessive movement and noise occurs. Laguna-rear- subframe

The above image is that of a Laguna rear arm mounting bush.

Also subject to checking for excessive movement  are the rubber bushes that steering racks can be mounted with, again the criteria when being checked is is there excessive movement or is the component insecure. The image below is of a pair of new steering rack mounting bushes beside a pair of worn bushes, two pairs are needed to mount the rack in this case a 54 reg mercedes c class.c-class_steering

In the above case the steering rack was moving enough to cause the ESP light to illuminate and for the ECU to limit the power produced by the engine.

Since the 20th of this month the ESP light being illuminated is a reason for rejection (failure)

Suspension Components

A number of suspension component failures have cropped up recently, beginning with a Nissan Micra 09 reg rear shock absorber, the wording of the Rfr is “serious fluid leak”. As can be seen in the image the dirt and dust on the whole shock absorber body and lower bush area has a damp wet look whilst the other components in the vicinity have a uniform dry dusty look to them, a sure sign the fluid is coming from the shock.

Surprisingly Nissan claim that this is fair wear and tear, so their 3 yr warranty doesn’t apply to this item. On an under 3yrs and under 24,000 ml vehicle ??

We also had a VW  Passat with a split cv boot for repair, the owner of the vehicle had looked under the vehicle and hadn’t been able to see the split, I took this image during the repair, because on these vehicles it is difficult to see the split in situ.

A customer brought in a 02 Renault Laguna complaining of a rubbing sound and smell of burning rubber, we put the vehicle on the ramp, and a quick look revealed the source of the noise and smell. The darker black ring is caused by the spring rubbing on the tyre.

A broken coil spring rubbing on the inside sidewall of the tyre and also touching the wheel rim.

The polished area of the spring is where it was rubbing on the tyre,

As a matter of course we also checked on the other side of the same axle and this revealed a crack in the base of the other coil spring, not easily seen, as the lower end of the spring is encased in a rubber sleeve, however the broken section moved easily when wiggled by hand and is slightly out of position.

A final coil spring on the rear of a Peugeot 207, 07 reg, the rubber spring seat out of position a sure sign that the lower section of coil is missing.

Coil springs again.

Even vehicles designed for off road use are not immune to the problem of broken coil springs, such as this one found on a Landrover. This particular vehicle doesn’t get much in the way of off road use, the occasional trip across a muddy caravan/camping site, but nothing in the way of serious off road use.

A follow on from my post regarding classic vehicles becoming exempt from Mot tests, it’s understandable when vehicles like this consul come in for test. The owner has owned it since the 1970’s when it was his engineering college project.

As such it gets very little road use and plenty of care and attention before venturing onto the road.
The underside was as immaculate as this engine bay

It’s always a pleasure to test vehicles like these and to chat to the owners and learn some of the history of the vehicle.

Witness marks

Often when conducting an mot I notice something before I begin to concentrate specifically on a set  of components.

Such an item were the presence of these polished spots on the subframe and driveshaft on a VW Polo as an indication or “witness” that something was amiss.

polished spots on driveshaft and subframe

Further investigation by looking at the driveshaft revealed that it was bent as you can see in the image above.  However the full extent of the distortion and runout is best shown in the following video.

Hearing the constant knocking from this area once in the roller brake tester made me question the hearing, common sense and sanity of the driver !

Don’t shoot the messenger.

As above please, we’re only doing our job, for your safety.

We had a vehicle presented this week for test, on beginning the test the abs light was illuminated indicating a fault with the abs system, the only reason for rejection noted. As normal we contacted the young lady and explained that it was a fail for this reason.The young lady told us the light wasn’t illuminated when she left it but that it occasionally came on and stayed on for a day or two.we made the offer to plug in the diagnostics machine to read the fault codes and extinguish the lamp, if it stayed out we could then retest and issue a pass, or she could take it away and return when the light was out for retest. She chose the first option, we extinguished the light, made note of the fault codes for her and issued the pass. Fine you would think, job done.

However 40 minutes later I had a call from her partner accusing me of putting the light on ! When I explained the light was on at the beginning of the test he told me I was lying, at this point I handed the phone over to the boss who went through the same explanation with the same result.

Contrary to what some people appear to believe Mot testers don’t make up their own reasons to fail a vehicle, we’re not out to rip people off doing unnecessary work, it’s just not worth the damage to our reputation.

When the bill was presented with the diagnostics listed as free of charge, there were no thanks or an apology for her partner’s attitude.

Other items this week, a Ford Ka presented with a leaking brake pipe union, sometimes we find this after a brake pipe has been changed and not checked with the brakes applied. What was unusual was the brake pipe appeared to be the original and no signs of work having taken place to account for the leak.

Some new reasons for rejection have been applicable since the beginning of the year with regards to ball joint rubber boots. This one was on an 03 Corsa anti roll bar link.

“… a balljoint rubber boot deteriorated no longer preventing the ingress of dirt etc”

seen removed from the vehicle , yup I think dirt will get in there

steering, brakes and suspension

We’ve had a number of items crop up this week, the first was on a ‘w’ reg Ford Ka, quite a bit  of corrosion reared it’s ugly head, not really surprising bearing in mind it’s age, but we also found a steering issue

the universal joint at the bottom of the steering column was excessively worn, allowing ecess free play at the sterring wheel, approx 30mm rather than the allowable 13mm. As it was a vehicle with power steering the joint was not available as a separate item, necessitating a replacement steering column, fortunately we were able to source a second unit rather than having to pay the main dealer price 0f £300+ for a new unit.

Friday afternoon we had a rather worried young lady in as her brakes were making a funny noise, a visual check through the wheels revealed one of the pads  breaking up, once the parts were ordered and on their way a stripdown revealed 3 of the 4 pads friction material had separated from the backing plate.

The pads were about 2/3rds worn but the vehicle had been relatively unused for a month or two .

Saturday brought a different problem in. An 06 Astra  for test had a badly worn tyre showing the cords.

  Once I began to check the steering and suspension on the ramp the reason for the inner edge wearing so badly became apparent.

The ball joint in suspension arm was badly worn, when it was driven into the brake tester to check the brakes a loud clunk from the front suspension was heard, had the vehicle come into the workshop when the clunk was 1st apparent the tyre may have lasted a few months more.

Peugeot and Citroen springs again.

Earlier in these posts I refer  to the way some peugeots and citroens have a habit of shredding their  front tyres when a coil spring breaks, mentioning a modification made under recall by the manufacturers consisting of a retaining shroud fitted around the base of the coil spring seat.
The above is an example of the retaining shroud in place, what cannot be seen in this instance is that the coil spring has broken and that the shroud has done its job and prevented the broken end of the spring falling down and shredding the tyre. The following image clearly shows how the spring has broken but remains securely on the spring seat. 

I should also mention that I have seen a broken spring that has managed to slip through the base of the shroud, so it seems it is not always successful in retaining the broken spring in place.

Suspension and prescribed areas

A number of items have cropped up this last week, a broken coil spring seems to be a regular occurrence, this one seen on a Renault Clio
In it’s normal position, rather than wheels free, the break was hardly noticeable, however once jacked up it was immediately spotted.

Following on from springs another regular occurrence are suspension arm bushes, the following images are from a ‘Y’ reg Honda Civic.
Again on initial viewing of it, it didn’t appear too bad, however on inspection of the underside of the arm it was clear that the bonding on the bush had failed allowing excessive movement, as the arm moved up and thus contacting the front subframe, leading to a heavy knocking over bumps. The same vehicle also had a problem with 2  antiroll bar links having become detached at the balljoints.Which were also making a characteristic knock over small bumps.

Then we had a Mazda MX5 suffering with some tinworm, the outer sills seem to suffer just forward of the rear wheel arches,Further inspection also revealed excessive corrosion to the sill closing panels inside the rear wheel arches, not something the owner would be expected to notice under normal circumstances.
All of the above would be spotted in good time if the vehicles were regularly serviced.

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