MOT fail front spring break, 3 year repeat!!?

[icarusi@hotmail]

I Just got a MOT fail on the nearside broken front spring. It failed 3 years before on both front spring and I did actually hear one break immediately prior to that MOT. I drove much more carefully since then because I wasn't sure if the rear springs would expire. I wasn't expecting another failure so soon. It's a very low mileage late 2009 model, and very carefully driven since the previous fails, so I'm now very suspicious about the replacement spring and the suspension. I did a quick search here and didn't find much grief on broken springs, unless it's too common to mention.

 

There's been no damage to tyre or wheel, no tracking or tyre wear problems. I'll know if there's other stuff when I get it fixed. I've been driving since '71 and *never* had a broken spring 'til now. From '80 on my cars had helical springs. I keep my cars for 10+ years until maintenance costs gets uneconomical.

 

There was a recent occasion when I went over a drainage grid, on the road separating the Fewston and Swinsty reservoirs. It looks like they've resurfaced at some time and haven't raised the grids to suit, There was a bit of a clunk but nothing massive, and that's the only memorable instance since the original springs broke.

 

Are current springs/suspensions now more rubbish at lasting than circa 10 years ago?

Edited 3 October, 2022 by icarusi@hotmail

[Breezy_Pete]

12 minutes ago, icarusi@hotmail said:

Are current springs/suspensions now more rubbish at lasting than circa 10 years ago?

 

Yes. 

One theory is that regulations to reduce harmful substances has resulted in paints that fail to protect the underlying metal surface so well as in 'days of old'.

Once corrosion starts through/under the paint layer, the likelihood of cracks starting is greatly increased.

[Carlston]

37 minutes ago, icarusi@hotmail said:

I Just got a MOT fail on the nearside broken front spring. It failed 3 years before on both front spring and I did actually hear one break immediately prior to that MOT. I drove much more carefully since then because I wasn't sure if the rear springs would expire. I wasn't expecting another failure so soon. It's a very low mileage late 2009 model, and very carefully driven since the previous fails, so I'm now very suspicious about the replacement spring and the suspension. I did a quick search here and didn't find much grief on broken springs, unless it's too common to mention.

 

There's been no damage to tyre or wheel, no tracking or tyre wear problems. I'll know if there's other stuff when I get it fixed. I've been driving since '71 and *never* had a broken spring 'til now. From '80 on my cars had helical springs. I keep my cars for 10+ years until maintenance costs gets uneconomical.

 

There was a recent occasion when I went over a drainage grid, on the road separating the Fewston and Swinsty reservoirs. It looks like they've resurfaced at some time and haven't raised the grids to suit, There was a bit of a clunk but nothing massive, and that's the only memorable instance since the original springs broke.

 

Are current springs/suspensions now more rubbish at lasting than circa 10 years ago?

 

What brand was the spring that broke after just three years?

 

[icarusi@hotmail]

8 hours ago, Carlston said:

 

What brand was the spring that broke after just three years?

 

I'm going to ask for the broken parts but I doubt the brand will IDable. 

[icarusi@hotmail]

Some interesting points in this similar topic https://www.pistonheads.com/gassing/topic.asp?h=0&f=135&t=1773743

 

Just had a search through that website and there's very little on springs failing regularly, although the MOT place and the place I'm getting the repair are saying it's fairly common, although they weren't qualifying the cause. Obviously potholes is a bigger current problem than it was and speed bumps have proliferated.

Edited 4 October, 2022 by icarusi@hotmail

[J.R.]

All conjecture, the only valid one was the link to this analysis of a spring with the exact same failure as our vehicles suffer.

 

https://www.sciencedirect.com/science/article/pii/S2213290214000182

 

I would add the following comments.

 

The article mentions shot peening and the difficulty of this process reaching the point where the stress cracking begins, OE springs have not been shot peened for decades except for race vehicles where the smallest lightest and hence most heavily stressed springs are used.

 

Springs on modern vehicles are much lighter and made from a smaller secion than on vehicles of the past despite the fact that the modern vehicles are at least 50% heavier, the springs are more highly stressed so the risk of fatigue cracking from any stress raiser is much higher, were they shot peened it would not be an issue.

 

The joke is that the springs are made from smaller wire which saves weight yet the vehicles never cease to get heavier and heavier, many components are getting lighter and lighter to counteract the weight of all the unecessary toys loaded onto modern vehicles.

 

The real culprit is closed end spring design which has the double effect of wearing away any corrosion protection, rubbing of the coils creating its own stress raiser in addition to any corrosion ones and increased stress at the transition point between the active and non active coils.

 

Does anyone know why manufacturers changed to a closed end spring design?

Edited 29 October, 2022 by J.R.

[mac11irl]

lighter thinner springs is not about counter acting the weight increase of modern cars, its about cost reduction. thinner springs use less materials thus are cheaper. plus thinner "eco friendly" cheaper paint.

 

also if the OP's mechanic bought cheap springs to do the replacement - unfortunately this is what happens

[J.R.]

Cheap or expensive springs the wire diameter and the latent failure mode will be the same.

 

The paint, thickness or lack thereof is a red herring.

 

I have editted my posting regarding weight saving, I had expressed myself badly.

[Breezy_Pete]

2 hours ago, J.R. said:

The paint, thickness or lack thereof is a red herring.

It's specifically mentioned in the abstract of the article you linked.  Yes you could say that whatever paint is used the same contact may remove it, but surely less so, the better the paint job and the better the paint?  I'm certain that many modern springs show rust far quicker than pre-millenium ones, not just in obvious contact zones.

 

...phosphate layer and painting around the contact zone were worn out due to contact and friction and resulted in corrosion and corrosion pits induced local stress concentration.

[J.R.]

Indeed they do, back in the day when I spent all my time repairing old bangers I dont even think they painted coil springs, every one I ever removed (to replace leaking struts, the springs rarely broke) was covered in rust it wasn't until I bought a 1980 Scirrocco that I was surprised to find black painted coil springs.

 

The paint is decorative, its the phosphate layer that gives the limited corrosion protection, if the ends did not rub they would last a lot longer but they are certainly higher stressed these days with the smaller wire diameter which is not desirable on a torsion spring.

Edited 29 October, 2022 by J.R.

[J.R.]

4 hours ago, Breezy_Pete said:

I'm certain that many modern springs show rust far quicker than pre-millenium ones, not just in obvious contact zones.

Maybe the phosphating has been dropped along with the shot peening.

[Ttaskmaster]

Well, I just had my second spring go since owning my Octy. Front left went about a year ago, this time it was the front right. Both were originals, AFAIK, and it's an '03 model so I suppose that's reasonably good going.

I've known it happen with other vehicles and my mechanic replaces them quite routinely, so I guess it's not that uncommon.