Corroded and snapped lower rear suspension arm

[Mister Tee]

Hi All, How long should rear suspension arms last before they get so corroded they break! Mine is 11 years old but the repairing garage and the AA recovery reckon they should never get like this in 11 years......thoughts please

[Magnet]

Hello Simon,

Thanks for posting the question of how long these critical components should last. It may be considered that 11 years is not long enough, but the location and design make these vulnerable. However, there will be other variables such as what region the car has been used in, that will indicate the likely amount of winter salt used, etc., so for me, I would think the question is generally unanswerable. 
What really concerns me here is how on earth a car with such an obviously corroded component like this would have passed an MOT in the last 12 months - and even if it did, why it wasn’t marked as an advisory. 
When did it pass its MOT Simon, and in terms of maintenance, how long have you owned it, and when was it last in a garage for servicing? 
If this were mine, I would be renewing both sides, and considering renewing the shock absorbers since they might also be rather/well rusted. 
Perhaps you can come back to us with the detail.

Kind regards,

Gareth. 

[Mister Tee]

Hi Gareth

Thanks for the response...answers to your questions:

• MOT was in May ( I also share your concern)
• Owned it since new
• Serviced on an annual basis
• Both sides renewed when this happened

I do appreciate it's almost an unanswerable question and I guess i was just wondering if anyone had shared the same experience

[Magnet]

Many thanks Simon, 

Apologies, but I really think you are mis-directing your concerns about how long these components should last, and your primary  concern should rest with the MOT centre and/or the servicing garage, both of whom have put you in a life threatening situation with this vehicle. 
To try to box this up:- Is the servicing garage also the MOT testing garage? 
Irrespective of your answer, I would be steering well clear of them/the pair of them, since they have both put you and yours in this unacceptably dangerous situation. 
You mentioned ‘both sides renewed -when happened’, which may suggest this didn’t happen yesterday -? 
If this rusted component failed within 3 months of the MOT date, then you could/should have notified VOSA, who would then have investigated the MOT station. This might well have saved others from a similar fete in the future. 
If this were mine:- my objective would be to find another trusted local garage, and an MOT station as soon as possible. 
Kind regards,

Gareth. 

[Mister Tee]

Thanks Gareth....I will follow up as advised

[cliffcoggin]

I agree with Gareth that incipient corrosion should have been detected long before it became so bad that structural failure occurred. That is precisely what the MOT test is for, so somebody is concealing something. A substantial piece of steel like that can not go from being acceptably fit for purpose in May to a complete failure in just five months.

As for the cause, I have never known this sort of failure on any car of any age so I wonder about corrosion or mistreatment. I see you are nowhere near the sea but salt treatment of the roads for de-icing in winter is a possible source of corrosion, particularly if you do not occasionally wash the underside of the car.  Mechanical mistreatment might involve jacking the car wrongly or at the wrong point thus weakening the steel. Both possibilities seem remote, but I can not think of another explanation. I believe you can be confident that there is no inherent defect in the original Audi components, so the failure must involve the way it has been used or treated.

[Mister Tee]

46 minutes ago, cliffcoggin said:

I agree with Gareth that incipient corrosion should have been detected long before it became so bad that structural failure occurred. That is precisely what the MOT test is for, so somebody is concealing something. A substantial piece of steel like that can not go from being acceptably fit for purpose in May to a complete failure in just five months.

As for the cause, I have never known this sort of failure on any car of any age so I wonder about corrosion or mistreatment. I see you are nowhere near the sea but salt treatment of the roads for de-icing in winter is a possible source of corrosion, particularly if you do not occasionally wash the underside of the car.  Mechanical mistreatment might involve jacking the car wrongly or at the wrong point thus weakening the steel. Both possibilities seem remote, but I can not think of another explanation. I believe you can be confident that there is no inherent defect in the original Audi components, so the failure must involve the way it has been used or treated.

Thanks Clifford....Jacking the car has never been an issue and the car has been maintained, serviced and generally looked after in the way that all of our cars have been. At 11 years it's probably the longest we have owned one but I agree it's the MOT issue that is most concerning

[Magnet]

Thanks Simon,

The bit about servicing/MOT station. 
Are these one and the same, and/or does the servicing garage get the car MOT’d at the same time as the service is carried out. 

Any intention of taking the arm to the MOT station for them to see what they have missed about 3 months ago!? 
Kind regards,

Gareth. 

[Mister Tee]

It's mainly the same garage Gareth, but servicing and MOT don't always exactly match as it depends on mileage