Broken suspension springs ??

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Buzzy-Beans
Joined: Tue 14 Nov, 2017 15:01
Posts: 15

  BMW other

Broken suspension springs ??

Post by Buzzy-Beans » Thu 23 Nov, 2017 21:37

I am currently doing research into the purchase of a Z3 or possibly if shoved a Z4 and am tracing back DVLA logged MOT history on any cars that I see which appear to tick most of my must have boxes.

One of the ever recurring failure notices recorded are broken road springs, both front and back................... why is this happening?

Having also spoken to several garage owners it would appear that most makes of cars now suffer from this perplexing problem!

If it is a known Z3/ Z4 problem are there any aftermarket springs that last longer than OE specification products?

Many thanks

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colb
Joined: Sat 05 May, 2012 23:46
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  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Broken suspension springs ??

Post by colb » Thu 23 Nov, 2017 21:58

Our road conditions are the main cause, deep potholes and the dreaded speed humps all over the place.
Z Springs should be up to the job as with other makes of cars oem quality springs should be ok, you might consider some uprated springs, they are out there. Age of our cars also has some bearing on the failure rate, a mechanical spring will degrade over time.
If you want to stay standard have a look here for Sachs branded springs, considerable savings with Carparts4less
https://www.carparts4less.co.uk/car-springs
Colb
1999 BMW 1.8 Z3
1998 Honda Deauville NT650V

Bumpa
Joined: Fri 23 Jun, 2017 21:31
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  Z3 roadster 2.2i

Re: Broken suspension springs ??

Post by Bumpa » Thu 23 Nov, 2017 22:43

Changing broken springs is one of the commonest jobs done by workshops these days. By the time I traded in my Mondeo it only had one original spring left. The new VW I replaced it with broke a spring after about 4 years. It isn't just a Z3 problem. It's a universal problem.

zedzedthree
Joined: Fri 29 Jul, 2016 14:16
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  blank

Re: Broken suspension springs ??

Post by zedzedthree » Sat 25 Nov, 2017 16:28

Bit more to this than simply road conditions.

Springs should be changed in pairs,I have experienced fractured springs at both ends of my Z3 in 9 years, so car has now had 4 springs fitted.
Why anybody would fit single replacement springs is beyond me!
Why would a car be on its last original spring unless corners are being cut?
Failure mode is well known-plastic coating fatigues and cracks,water + road salt enters and resultant corrosion leads to a highly stressed local weakness which then worsens as spring collapses ans fault area widens=more water entry=failure.
All my replacements were fitted with care not to damage or scrape coating and treated to prevent rusting using Dinitrol.

Buzzy-Beans
Joined: Tue 14 Nov, 2017 15:01
Posts: 15

  BMW other

Re: Broken suspension springs ??

Post by Buzzy-Beans » Sat 25 Nov, 2017 17:05

zedzedthree wrote:
Sat 25 Nov, 2017 16:28
Bit more to this than simply road conditions.

Springs should be changed in pairs,I have experienced fractured springs at both ends of my Z3 in 9 years, so car has now had 4 springs fitted.
Why anybody would fit single replacement springs is beyond me!
Why would a car be on its last original spring unless corners are being cut?
Failure mode is well known-plastic coating fatigues and cracks,water + road salt enters and resultant corrosion leads to a highly stressed local weakness which then worsens as spring collapses ans fault area widens=more water entry=failure.
All my replacements were fitted with care not to damage or scrape coating and treated to prevent rusting using Dinitrol.
Geeeeez the springs are plastic coated, no wonder they break.

Is there a manufacturer of springs who doesn't plastic coat them so that from day one you can coat them in Dinitrol, Waxoil or any such similar coating?

therealdb1
Joined: Tue 25 Jun, 2013 22:47
Posts: 246

  Z3 roadster 2.0

Re: Broken suspension springs ??

Post by therealdb1 » Sat 25 Nov, 2017 17:09

This was a common failure on the Vauxhall Cavalier / Chevette in the mid to late 1970's so it is not a new phenomenon.
It is not a particularly difficult or expensive repair and road springs have to be seen as consumable items like suspension bushes or shock absorbers. It is just that rather than gradually wearing out they suffer catastrophic failure and the first you know about it is a dropped ride height or MOT refusal.

petecossie
Joined: Wed 11 Apr, 2007 14:13
Posts: 125

  M coupe S50
Location: Billingham

Re: Broken suspension springs ??

Post by petecossie » Sat 25 Nov, 2017 18:38

The BMW E46 M3 is also renown for breaking rear springs. The 2003 car I purchased back in 2009 had to have a pair of new OEM rear springs fitted just before I bought it as when the seller took for a new MOT it failed, offside rear spring broken. I had the car for 3 years and had to get another set fitted as again the offside rear was found to be broken just before I sold it in 2012.
Pete C

2000 Z3M Coupe - Cosmos Black Metallic/Black Interior.
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Previous BMWs
2003 E46 M3 6 speed manual - Carbon Black/Black Interior.
2000 Z3M Coupe - Cosmos Black/Black Interior
1986 M635
1985 E28 M5
1983 E28 528i Alpina

Bumpa
Joined: Fri 23 Jun, 2017 21:31
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  Z3 roadster 2.2i

Re: Broken suspension springs ??

Post by Bumpa » Sun 26 Nov, 2017 10:08

therealdb1 wrote:
Sat 25 Nov, 2017 17:09
It is just that rather than gradually wearing out they suffer catastrophic failure and the first you know about it is a dropped ride height or MOT refusal.
Not on my VW. All I noticed was a gentle clicking noise when riding over bumps. Rear spring had snapped but you would never know from looking at the car or driving it. The springs on my Mondeo were replaced singly by my local workshop, and so was the VW one by a different workshop. The cars were perfectly all right with one new spring and one original. As for powder coating springs - what a daft idea, but it's commonly done. I don't like powder coating at all. It's fine until a small chip occurs and then the water and rust get underneath and it comes off in large flakes. Chassis paint does a better job on subframes and suspension arms.

Buzzy-Beans
Joined: Tue 14 Nov, 2017 15:01
Posts: 15

  BMW other

Re: Broken suspension springs ??

Post by Buzzy-Beans » Sun 26 Nov, 2017 17:02

So when it comes to the Z3 what are the best springs to go for, and if they were to come powder coated what is the best way to remove the blessed stuff and then recoat it in Waxoil or similar?

gookah
Z Register member
Joined: Thu 07 Aug, 2008 10:51
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  Z3 roadster 2.8

Re: Broken suspension springs ??

Post by gookah » Sun 26 Nov, 2017 19:34

zedzedthree wrote:
Sat 25 Nov, 2017 16:28

All my replacements were fitted with care not to damage or scrape coating and treated to prevent rusting using Dinitrol.
That wont prevent it all together,
Salt/Grit gets on the spring base of the shocker or trailing arm
The movement of the spring then presses it on the grit and it punctures the coating. Once done, its a time bomb rotting from inside out,
Plastic coating is stupid. they always seem to break near the bottom where it has sat on the grit.
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Z3 2.8 Progress Journal (Mine)
Z3 1.9 Sport Progress Journal (Wifey's)

I have an element of 'M-styling' on my car, If that's a good enough reason for the manufacturers to adorn a 320 with the M badge, then its certainly a good enough reason for me..

therealdb1
Joined: Tue 25 Jun, 2013 22:47
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  Z3 roadster 2.0

Re: Broken suspension springs ??

Post by therealdb1 » Mon 27 Nov, 2017 00:06

Rear spring had snapped but you would never know from looking at the car or driving it.
I bet the MOT tester would have spotted it. They always seem to on my cars! Its a bread and butter job for them these days.

zedzedthree
Joined: Fri 29 Jul, 2016 14:16
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  blank

Re: Broken suspension springs ??

Post by zedzedthree » Mon 27 Nov, 2017 12:31

When my OSR spring (the first failure) was picked up at MOT,the tester was taken aback when I thanked him.There was no obvious settling,car drove alright and being winter,my driving was proportionate and no fast corners etc.
I did not suggest that Dinitrol was a sure fire solution to prevent a recurrence however the coating must be cracking by now,especially on the rears that have been on for years and a visual check shows no flaking so it appears ingress of water has been delayed despite ultimately being inevitable.
My replacements have been OEM Sachs.
Thank goodness we have annual MOT testing-just think how many other poorly maintained cars are driving around with broken springs.
Coil springs have a finite life and are subject to settling and worse,fatigue.This is why they should always be replaced as a pair,not to mention havingtogo through the process again when the old fatigued remaining spring gives in.

PaulI
Joined: Sun 28 Dec, 2003 19:37
Posts: 20

  Z3 roadster 2.8
Location: Weybridge, Surrey

Re: Broken suspension springs ??

Post by PaulI » Wed 29 Nov, 2017 16:47

I had my first MOT spring failure this year on my trusty Astra wagon. I bought a new pair, watched a YouTube video, and replaced both sides in under 1 hour myself1 Just jacked up the rear, let handbrake off and then there is enough room to wiggle the spring out, and pop the new one in.

Buzzy-Beans
Joined: Tue 14 Nov, 2017 15:01
Posts: 15

  BMW other

Re: Broken suspension springs ??

Post by Buzzy-Beans » Thu 30 Nov, 2017 20:55

zedzedthree wrote:
Mon 27 Nov, 2017 12:31
Coil springs have a finite life and are subject to settling and worse,fatigue.This is why they should always be replaced as a pair,not to mention havingtogo through the process again when the old fatigued remaining spring gives in.
As an ex very long term LR Defender owner, in all of the tens of thousands of miles driven over some atrocious roads and off road conditions, I never had a single coil spring failure and I never heard of any on any of the LR specific forums I frequented.
So as this is the case could it be that relatively lightweight coil springs are more prone to failure?

zedzedthree
Joined: Fri 29 Jul, 2016 14:16
Posts: 18

  blank

Re: Broken suspension springs ??

Post by zedzedthree » Fri 01 Dec, 2017 11:40

An interesting observation on LR Defender springs Vs Z3,have known quite a few LR variant ( Range Rover/Discovery) owners who also had no broken springs.
The Z3 was launched and equipped with progressive OEM springs with relatively small diameter coil ends as US pre sales testing found a buyer preference for a little initial softness compared to solid springs.

My experience has been that the initial failure has been at the end turn of the spring (common also on other car makes) and having seen quite a few on other Z3's this seems to be the failure mode but my first broken spring was a rear that failed at around mid way,both fronts were breaking from the ends.

therealdb1
Joined: Tue 25 Jun, 2013 22:47
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  Z3 roadster 2.0

Re: Broken suspension springs ??

Post by therealdb1 » Fri 01 Dec, 2017 13:07

zedzedthree wrote:
Fri 01 Dec, 2017 11:40
have known quite a few LR variant ( Range Rover/Discovery) owners who also had no broken springs
Are they the ones with air suspension!!! :lol:

vzh7gk
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Re: Broken suspension springs ??

Post by vzh7gk » Fri 01 Dec, 2017 15:51

That did break...
Graham (G4FUJ)
Prescott marshal and Hill Controller
Found another Z3 so back here after a long break :) 1999 1.9, Palmetto Green
1 Morgan 4/4 (selling in Spring) and a Land Rover 90 (keeping forever)

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Z3crazy
Joined: Thu 04 May, 2017 14:37
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  Z3 roadster 1.9i

Re: Broken suspension springs ??

Post by Z3crazy » Tue 05 Dec, 2017 14:39

colb wrote:
Thu 23 Nov, 2017 21:58
Our road conditions are the main cause, deep potholes and the dreaded speed humps all over the place.
I live abroad and (up until recently) came over on a regular basis to visit the family in Brecon (Wales). I can only say that British roads are, in general, absolutely appauling. It's not just the pot holes and speed bumps, it's the drainage and manhole covers that remain at a fixed position when the road around them is re-surfaced and raised. This can often cause a 4" dip. Only way i could avoid this was driving against the white line (in a LHD car) down country roads between Newport and Brecon (not that the M20, M26, M25 and M4 are any beter). :(

It's great to get off the boat in Dunkerque and drive on "flat" tarmac all the way to the Netherlands. :)

And...... if they need to resurface a motorway over here it's a damn sight quicker, and if you drive past them EVERYBODY is working and doing something to do with road works.

So, it's not a surprise that changing springs is becoming a national passtime.

Dave
If it ain't broke, don't fix it
Z3 1.9 2000, Cosmos Schwartz

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