thelynxeffect
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| posted on 22/9/18 at 11:01 AM |
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Bad experience with mushrooms!!
Not the ones that grow in fields but the ones that convert the Sierra uprights to double wishbone suspension!
I had recently fitted some new cycle wing brackets and had taken the car out for a quick shake down to make sure the wings didn’t fly off. At about
50mph all was going well until the steering went very light and I drifted towards the verge!
Yep the mushroom had popped out of the upright!!
 
Description
After some quick road side fettling I managed to get it back in and clamped it as tight as I could (I had last torqued it to 120nm) and slowly drove
the mile or so home.
After some research I soon discovered the lack of a secondary fixing as per the IVA. No idea how it got through without but I understand why they
insist on it!!!
I have now fitted some m8 bolts through the upright into the ‘shroom so should be all good now.
 
Description
 
Description
[Edited on 22/9/18 by thelynxeffect]
[Edited on 22/9/18 by thelynxeffect]
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Slimy38
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| posted on 22/9/18 at 11:40 AM |
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Out of interest, what would the secondary fixing have been when it was on the Sierra? Is it just a clamp originally?
The suspension setups that I can think of mostly rely on the bolt itself fitting in a dent in the upright, so that the bolt has to be completely
removed. It doesn't look like the Sierra setup is the same?
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thelynxeffect
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| posted on 22/9/18 at 11:46 AM |
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The original strut shock has a bracket that attached to the pinch bolt so it couldn’t work loose and come out.
[Edited on 22/9/18 by thelynxeffect]
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Slater
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| posted on 22/9/18 at 03:07 PM |
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That is a good idea. I think I will do the same on mine. Thanks for posting.
Why do they call Port Harcourt "The Garden City"?...... Becauase they can't spell Stramash.
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thelynxeffect
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| posted on 22/9/18 at 03:40 PM |
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This old thread has more detail.
http://www.locostbuilders.co.uk/viewthread.php?tid=174028
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daviep
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| posted on 22/9/18 at 06:57 PM |
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Glad to here you escaped unscathed. You need to find out why the mushroom was able to come out, if the mushroom fits the upright correctly and the
bolt is torqued correctly then there is no way it should be possible for it to come out, the clamping force should be huge. If the clamping force
cannot hold the mushroom in then you are relying on your secondary retention leaving you without a back up again.
The fact that you managed to get the mushroom back in at the side of the road with the bolt still in situ and tight would suggest that the mushroom is
probably undersize to begin with. When changing dapmers on production cars often you need to hammer a wedge or chisel in to the slot in order to
spread the upright before you can get the strut in/out of the upright.
Other observation is that you need to clean all the rust from the bore of the upright, if you clamp it up tight with rust between the upright and the
mushroom as the suspension vibrates the rust will slowly turn in to dust and fall out of the joint and eventually the joint will become slack as the
bore effectively gets bigger.
Cheers
Davie
“A truly great library contains something in it to offend everyone.”
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thelynxeffect
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| posted on 22/9/18 at 07:20 PM |
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Davie, you are bang on the money with your observations, when I stripped them to fit the secondary bolt I spent quite a while cleaning the surface
corrosion off the mushroom and the face of the upright, there was even some paint in there. I also fitted new M12 8.8s pinch bolts which I clamped to
140nm.
Fortunately when it popped out I wasn't far from home so I had the wife bring my tool box to me, I certainly did' just pop it back in, the
only hassle was doing it without jacking the car.
It is an interesting point you make about the size of the mushroom though, i might whip them out at some point and put the calipers across them out of
curiosity. They are aluminium and I think I would rather steel ones but the winter refit may see some new uprights so I'll leave it for now.
Cheers for your reply
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daviep
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| posted on 22/9/18 at 07:23 PM |
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Just noticed that you have used an A2-70 bolt for your secondary retention, you need to change this, a normal 8.8 is almost 50% stronger a 10.9 is
almost twice as strong. Generally speaking it is bad practice to use stainless bolts on structural joints unless the joint is designed specifically
designed for them.
Cheers
Davie
“A truly great library contains something in it to offend everyone.”
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DRC INDY 7
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| posted on 22/9/18 at 07:25 PM |
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I have drilled mine and roll pinded tham and had no problems since i did it in 2008
https://www.facebook.com/groups/462610273778799/
Puddle Dodgers Club
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daviep
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| posted on 22/9/18 at 07:27 PM |
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quote:
Originally posted by thelynxeffect
Davie, you are bang on the money with your observations, when I stripped them to fit the secondary bolt I spent quite a while cleaning the surface
corrosion off the mushroom and the face of the upright, there was even some paint in there. I also fitted new M12 8.8s pinch bolts which I clamped to
140nm.
Fortunately when it popped out I wasn't far from home so I had the wife bring my tool box to me, I certainly did' just pop it back in, the
only hassle was doing it without jacking the car.
It is an interesting point you make about the size of the mushroom though, i might whip them out at some point and put the calipers across them out of
curiosity. They are aluminium and I think I would rather steel ones but the winter refit may see some new uprights so I'll leave it for now.
Cheers for your reply
Haha that makes a bit more sense 
Just noticed that I sound a bit doom and gloom, sorry didn't mean to come over that way.
Cheers
Davie
“A truly great library contains something in it to offend everyone.”
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CosKev3
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| posted on 22/9/18 at 07:46 PM |
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quote:
Originally posted by Slimy38
Out of interest, what would the secondary fixing have been when it was on the Sierra? Is it just a clamp originally?
The suspension setups that I can think of mostly rely on the bolt itself fitting in a dent in the upright, so that the bolt has to be completely
removed. It doesn't look like the Sierra setup is the same?
With the strut passing threw the upright and the weight of the car pushing the strut down there is no way on a Sierra the strut could come out of the
upright!
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thelynxeffect
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| posted on 22/9/18 at 07:55 PM |
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quote:
Originally posted by DRC INDY 7
I have drilled mine and roll pinded tham and had no problems since i did it in 2008
Never thought of pinning, good idea, much simpler.
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SJ
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| posted on 22/9/18 at 08:13 PM |
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Mine have been in without any secondary fixing for 8 years now, and haven't budged. Seems to me there is very little force applied so for the
mushroom to come out I would guess it must have been very loose.
I'll be looking at adding something to mine after seeing this though.
Lucky that it didn't cause more of an accident for the OP.
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ianhurley20
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| posted on 22/9/18 at 09:58 PM |
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I drilled a hole and put a 6mm bolt through as a secondary fitting for IVA after seeing someone else having one pop out near Blyton a few years ago.
No issues ever with mine since. Shouldn't be needed but its good practice I think
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Mr Whippy
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| posted on 23/9/18 at 01:56 AM |
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It is surprising that there's a force generated even remotely strong enough to pull that out considering its just the arm swinging. All forces
should really be horizontal other than the momentum of the arm. Just how free are your arms? The bushes aren't binding are they?
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Daf
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| posted on 23/9/18 at 10:38 AM |
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I have some new steel mushrooms on the shelf here if you're after any
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Irony
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| posted on 24/9/18 at 09:39 AM |
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This exact same thing happened to me a it was flipping scary to see the wheel flapping about. I managed to somehow fit the bugger back in on the
roadside and drive very very cautiously back home. After a search on here I found a few threads and I am surprised that no one mentioned not having a
secondary fixing is a IVA fail. The IVA man never mentioned the fixings needed to be a certain strength.
Having thought back over my experience I don't think the forces generated in general driving cause the mushroom to come out. I turned down a
very very bumpy road and it was a huge dip on that side that jarred the mushroom out. I think I used a M6 allen headed bolt and tapped the mushroom
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Irony
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| posted on 24/9/18 at 09:43 AM |
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See this post
Mushroom Post Link
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thelynxeffect
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| posted on 27/9/18 at 07:45 AM |
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quote:
Originally posted by Irony
This exact same thing happened to me a it was flipping scary to see the wheel flapping about. I managed to somehow fit the bugger back in on the
roadside and drive very very cautiously back home. After a search on here I found a few threads and I am surprised that no one mentioned not having a
secondary fixing is a IVA fail. The IVA man never mentioned the fixings needed to be a certain strength.
Having thought back over my experience I don't think the forces generated in general driving cause the mushroom to come out. I turned down a
very very bumpy road and it was a huge dip on that side that jarred the mushroom out. I think I used a M6 allen headed bolt and tapped the mushroom
Same mate, the road I was on was a very bumpy back road, much worse than a regular driving road, I guess the vertical motion just got the better of
the compression force. Additionally I was running the suspension quiet soft so there was a lot of movement in the wishbones.
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AntonUK
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| posted on 1/10/18 at 12:37 PM |
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mine have a plate welded to the insert that then slides into the gap between the bolt holes.
Build Photos Here
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