Broken rear coil spring

[andoland Senior Member Find all posts View Profile Close andoland]

I just got back from a long trip across the Anne Beadell Hwy, Connie Sue Hwy, Sandy Blight Junction Rd, Gary Junction Rd and Madigan Line. On the Madigan Line I could hear a clunking noise from time to time but I'm buggered if I could figure out what it was. I checked for broken shocks, loose bolts, I greased the drive shafts in case they were binding, etc., but obviously didn't look properly. When I got home and unloaded the Prado I noticed it was leaning to the left and discovered this.



The springs are aftermarket and I can only put it down to a manufacturing defect. When I looked at the fracture face there is a small discoloured area which suggests the crack initiation site - you can see this at the top of the fracture face in the photo. These springs have done the CSR, French Line and Madigan Line over a period of 4 years before this trip.

Has anyone else experienced a coil spring failure like this? I have never heard of it before. I was able to get the spring replaced straight away and this isn't a post about warranty, I'm just curious as to how common or uncommon this is.

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

Thats not gone well.
I think your lucky that the spring has somewhat interlinked itself up like that and not fallen loose/collapsed/caused further damage.
I have no personal experience, but I'm sure its happened to people before.

[andoland Senior Member Find all posts View Profile Close andoland]

Yep, very lucky. One of the reasons I didn't pick up the problem is that apart from the noise, which was intermittent, there didn't actually seem to be anything not working properly.

In hindsight I'm very glad that I didn't discover the problem out on the Madigan Line because then I would have been in a position where I had to try to fix it/stabilise it and/or make a decision to head out to the nearest town to get it fixed. Luckily for me it held together.

[Anth120playdo Banned Find all posts View Profile Close Anth120playdo]

Interesting. Heard of a couple but never seen or had it here.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Lucky you didn't travel along any really rough roads or you could have got stuck somewhere.

[andoland Senior Member Find all posts View Profile Close andoland]

Lucky you didn't travel along any really rough roads or you could have got stuck somewhere.

Hmm, yes

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

Hey,

Very lucky no serious damage occurred.

With a shear like that, it is likely that the tempering of the coil was not homogenous, ie big temperature gradients, seems very peculiar.

Could you specify who the manufacturer of this after market coil is?

Best

Mark

[Rainman Advanced Member Find all posts View Profile Close Rainman]

I just got back from a long trip across the Anne Beadell Hwy, Connie Sue Hwy, Sandy Blight Junction Rd, Gary Junction Rd and Madigan Line. On the Madigan Line I could hear a clunking noise from time to time but I'm buggered if I could figure out what it was. I checked for broken shocks, loose bolts, I greased the drive shafts in case they were binding, etc., but obviously didn't look properly. When I got home and unloaded the Prado I noticed it was leaning to the left and discovered this.

[ATTACH=CONFIG]21105[/ATTACH]

The springs are aftermarket and I can only put it down to a manufacturing defect. When I looked at the fracture face there is a small discoloured area which suggests the crack initiation site - you can see this at the top of the fracture face in the photo. These springs have done the CSR, French Line and Madigan Line over a period of 4 years before this trip.

Has anyone else experienced a coil spring failure like this? I have never heard of it before. I was able to get the spring replaced straight away and this isn't a post about warranty, I'm just curious as to how common or uncommon this is.

I had a similar failure on the Canning Stock Route last year, spring broke heading into Durba Springs. Without going into detail it seems it was caused by mismatched springs (Dobinson) and shockies (Bilstein). :cry:

[andoland Senior Member Find all posts View Profile Close andoland]

Rainman,

It's difficult to see how a spring failure could be caused by mismatch between springs and shock absorbers. I'm guessing that the spring manufacturer/seller told you this? What did you do to get mobile again on the CSR?

Whitey,

I'm still blaming the failure on an inclusion in the steel or surface defect at that dark point you can see on the fracture surface. For what it's worth the springs are Old Man Emu, but I don't see this as a slight on ARB or their product - it's one of those very, very few defects that make it through the system. I've been extremely happy with the suspension and didn't hesitate to have the springs replaced with exactly the same ones.

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

Hey andoland and Rainman,

Could you both specify the free height and spring rate of the coils that failed. Also, what are the closed/open lengths of the shocks that you are both running in the rear?

As you were both on big trips, I would suspect that these failures are due to heavily loaded vehicles (neither photo shows airbags?), and defective coils that have snuck through manufacturing quality control.

Rainman, I doubt that a mismatch between coil and shock is responsible, otherwise we would see this everywhere as people are using lots of different after market combinations with great success.

Suspension geometry on the rear may also be a contributing factor, with short open length shocks taking a beating and topping out on heavy corrugations leading to sudden big loads on the coils in deep dips.

Best

Mark

[andoland Senior Member Find all posts View Profile Close andoland]

Could you both specify the free height and spring rate of the coils that failed. Also, what are the closed/open lengths of the shocks that you are both running in the rear?

I've got no idea of spring rates and shock lengths. I have OME 200kg constant load, 50mm lift springs in the rear and OME shocks - that's the best info I can give you.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

the tempering of the coil was not homogenous

Hey, we'll have none of that talk on here thank you.

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

I've got no idea of spring rates and shock lengths. I have OME 200kg constant load, 50mm lift springs in the rear and OME shocks - that's the best info I can give you.

Google tells me you have likely got this setup -

[Rainman Advanced Member Find all posts View Profile Close Rainman]

Rainman,

It's difficult to see how a spring failure could be caused by mismatch between springs and shock absorbers. I'm guessing that the spring manufacturer/seller told you this? What did you do to get mobile again on the CSR?

Its a long story, hopefully I wont bore you too much but in the two 4x4's I've owned, I've had 5 different setups, including OEM and to be honest, I haven't been able to tell the difference between any of them, so I admire all those on here, and elsewhere who claim to be able to feel the differences down to the enth degree. So as you can see, I'm not claiming to be an expert in any way.

I had Dobinson suspension all round and the shockies were due for replacement so I contacted a former Pradopoint member who I considered had a wealth of knowledge in this field and purchased four Bilstein shocks of him, reputably specifically set up for my 90 series. I had them fitted, keeping the Dobinson rear springs as measurements showed they hadnt dropped since the original install.

Out on the Canning, I was not as loaded up as everyone else but they all commented on how I "bounced" up the dunes while others powered up and over. Coming into Durba I crested a dune and on the way down heard a loud bang, I got out and found the left spring broken. With careful nursing I managed to get the vehicle out at well 9 and drove home to Perth.

I took the car to a suspension shop and told them to replace the rears with Kings. A little while later they called me in to show me that with the current Bilstein shockies at full extension, the new Kings would fall out, so I would have to replace the shocks as well. It was their opinion that the Dobinsons had been too soft and the Bilsteins were too long at full extension.

I contacted the original vendor and was advised that the shocks I bought off him should have been installed with the springs (that I didn't purchase) he also quoted me on, so it was indeed a mismatch.

The shocks fitted to the rear were F4-BE5-G604-MO while the Dobinson springs were C59-137V, perhaps some of those more knowledgeable than me can comment on this combination?

Currently I have King HD springs and Tough Dog shocks fitted, but they haven't seen any action. I'm a bit dubious of the Tough Dogs going on opinions of others - but thinking like that is kind of what got me into this situation in the first place. For my next 4x4 I think I'll just keep it stock standard, after all I cant tell the difference.

[Rainman Advanced Member Find all posts View Profile Close Rainman]

I've got no idea of spring rates and shock lengths.

I'm with andoland on this one.