And the failed springs on the astra went about 2/3 way down from the top - not the ends.
Or 1/3rd up from the bottom !
I took them to the recycling about a month ago, but may have some pictures somewhere......
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>> being people in the know, they've all highlighted that the failure has been through localised stresses leading to corrosion, from poor design or materials.
Mmm, I've read these letters published in PE too. I've been giving this a little thought, reviewed some spring design calcs, and I don't fully buy into the logic about the failures purely being brought about by the end detail.
The end detail of most compression coil springs is a bit of a bodge, and I can't think of a design that would not result in a stress concnetration of one form or another. Even a ground spring end only sits flat and true at one load - coil springs are effectively torsion bars which are packaged by winding them up helically. If the ends are ground flat while the srpings are unloaded, they won't sit flat when the weight of the car is borne by them.
The real issue must be a relaxation in the fatigue testing requirements that the suspension is subject to. It's entirely likely that this aspect of suspension development has been relegated from a requirement verified by test to one which is verified by analysis. This is OK as long as the loads, and boundary conditions are correctly analysed.
The fatigue behaviour of the materials, even under corrosive conditions, are very well known. The loads are simple enough to estimate - one possible, though arguably conservative, loadcase is to consider the stress range between full bump and full rebound, and assess against survival of 10^7 cycles.
The boundary conditions are more difficult to deal with properly - in full detail, the contact between the spring and the keeper varies as the suspension deflects, there will be some friction/slippage - it's not a simple analysis. Calculating the stress level in a fatigue calculation is always fraught with difficulty - the fatigue life is very strongly determined by the stress range. If you make an error or use an excessively conservative assumption in determining this stress range, the adequacy if the resulting design solution will be questionable, one way, or the other.
One thing that is really difficult to deal with is fatigue crack initiation. It's very stongly dependent on the local surface conditions of the steel and the atmosphere. If the springs used differ from those tested, even in seemingly insignificant detail, their life to crack initiation, and thence to failure may be different from behaviour observed during test.
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This week I have just purchased a Vauxhall vectra 05 diesel estate from a from a small trade dealer. When I carefully go over a speed bump (lots near where I live) as the car comes back down off the bump it make a sort of crunching noise as if there maybe a problem with the suspension coil. It does not happen when I approach speed bump straight on, more when passenger side is low and driver?s side up on bump?? It seems worse when the children are in the back of the car. The noise appears to come more from the front passenger side.
Sorry this is not very technical like the above entry but I am wondering if the coil/spring on the front passenger side could be gone. The car came with full one year MOT and hpi check. Would welcome any helpful advice. Don't know whether to get RAC check (bit late I know)?
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That sounds more like an anti-roll bar bush/bearing problem than a coil spring.
When you go over a bump "straight on", the anti-roll bar doesn't get twisted, and doesn't carry any load - when you go over one side first, the anti-roll bar twists, carries load, and transfers wheel load from one side of the car to the other.
Ask the garage from where you purchased the car to check over the suspension, paying particular attention to the anti-roll bar, and its mountings and bearings.
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Very common noise on vectras and saabs, my vectra did the same especially on cold mornings, definately anti-roll bar bushes.
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definately anti-roll bar bushes.
Agreed. My previous 2004 Vectra also did it, but my current 2006 one doesn't. Was told it was just dry rubber bushes and could be resolved more often than not with a squirt of WD-40 or silicone spray.
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Wow! Thanks. Didn?t expect so many knowledgeable replies. I?m relived to know what problem is now and it does not sound too bad. Apart from trying the WD40, is it a big/expensive job if the trader doesn?t agree to help?
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No, cheap as chips, bushes are cheap and easy job to do
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So it's July 2010. My son bought a 2005 Vectra C last Summer. I took it for an MOT last week. One fractured front n/s spring, one fractured rear o/s spring. Plus n/s and o/s drag link wear (drumsticks). At first I was annoyed and asked my son what he had been doing. Then I started to read up on the topic.
Never, and I mean never, in my 43 years of motoring have I personally had a vehicle that suspension springs broke. The Vectra C is a fine car to drive, with good safety and road handling. But these coil springs look more suited to a much lighter vehicle to me. Comparing the whole structure to my own Nissan Primera P12 suspension set-up there is no comparison, although the Vectra roadholding and handling is keener.
So altogether, including 2 new front tyres, 4 springs (common sense to replace all 4), 2 new drag links etc = £750. Be warned this is a common fault and could in fact be a disastrous fault if the spring totally collapsed or carved into the tyre at high speed.
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We have a 55 reg Signum 2.2 petrol. bought in Summer 2006. We still have it with 90k on the clock as at Feb 2017. Quite a few years go my wife was doing 60 mph round the St Albans orbital, pulled off into a shop car park and BANG, car sat down at the N/S/F. The road spring had snapped in the middle, and the broken end missed the tyre by 10 mm, but machined a groove in the wheel aluminium :-( Fast forward to about 2 years ago, and another bang from the O/S/F. This time the spring ahd snapped half a turn up from the spring seat, but no collateral damage this time. Submitted a full letter and full Vehicle details to VOSA after the first problem, but they then wanted `their' form filled out. Jobsworths :-( Now we have had two new front springs and struts fitted as a precaution......my Independent Garage reckons this is a very common problem. I have had much better service from them than the Vx Main Dealer, now closed down !
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Seems to be quite common these days as some car makers cut costs by using the cheapest supplier and not applying the proper quality standards for the product.
Very sloopy, and as usual our Government depts are spineless.
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Agree 100% with sandy.
My Passat estate recently had the N/S rear spring break.
The car was sitting on the drive when I heard an almighty bang from the vehicle.
On inspection, spring had broken about 1/3rd way up.
A visual inspection of the break showed a flaw in the metal causing a local weakness.
!st broken spring in 49 years of motoring.
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