zetec
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| posted on 5/7/10 at 04:50 PM |
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Wishbone failure.
Went out for a quick spin last night. Moving in traffic, just 5-10 mph up to some traffic lights, braked and heard a sharp crack and steering went a
bit strange. Pulled over and found the front bottom wishbone inner joint had snapped...glad I was going slow. It just held on long enother to get me
to the kerb. Tow truck home, first time ever, and now awaiting a pair of replacment wishbones.
I've always been a bit concerned about a failure in this area as there appears to be no built in safety factor if the joint does give up. I
check the car over every year before going back out on the road after winter and all fine then.
Should these parts be changed as a matter of course and be on the safe side?
Put me off a little which is a shame as I've always been 100% confident in the car.
[Edited on 5/7/10 by zetec]
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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beaver34
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| posted on 5/7/10 at 04:56 PM |
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i had this problem, did one side
all fine, then other side went so do both i got lucky both times tbh
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2cv
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| posted on 5/7/10 at 04:57 PM |
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I'd be interested in seeing a picture if this is possible please.
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zetec
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| posted on 5/7/10 at 05:19 PM |
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Not nice viewing...
 
Rescued attachment IMG_0595.jpg
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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turbodisplay
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| posted on 5/7/10 at 05:24 PM |
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That is scary. Looks like either the effect of haz or the tube join.
Darren
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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procomp
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| posted on 5/7/10 at 05:25 PM |
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Hi
Common problem. The key as to why is shown by the rust between the mild steel crush tube and the plastic bushes as visible in the pic. As being
discussed on an other thread the bushes need to be free and compliant otherwise the end result is as has happened.
It really is about time the world of kitcars moved from these cheap nasty bushes in ill fitting housings with wrong length inner pivots and started to
supply a product that is fit for the purpose.
Cheers Matt
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JeffHs
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| posted on 5/7/10 at 05:27 PM |
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I'm no expert, but I would say that is a very unusual failure. Am I right that the bush tube has failed and burst apart, just by the weld?
Failures alway occur in the heat affected zone due to embrittlement, but I would not have expected the tube to split.
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zetec
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| posted on 5/7/10 at 05:33 PM |
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I'll check to see how free the bushes are on the other end and the other wishbone....What is the answer if the basic desin is at fault, do the
more mainstream "7" /Caterham builders do something different? If so I'll pay the extra!
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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procomp
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| posted on 5/7/10 at 05:50 PM |
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Hi
What is needed is proper bushing designed to do the job intended in housings that are machined to a very tight tolerance made from quality material
not just ERW tubing.
There is a very good reason why some kits cost more than others and it's when problems like this arise that you become aware of just why and
where that extra money charged goes.
Cheers Matt
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zetec
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| posted on 5/7/10 at 06:02 PM |
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So can you adapt my wishbones to something a little more confidence inspiring without having to chop the chassis brackets off? Pics on your site look
like you use rod ends on the front wishbone inner joints.
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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rusty nuts
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| posted on 5/7/10 at 06:14 PM |
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quote:
Originally posted by procomp
It really is about time the world of kitcars moved from these cheap nasty bushes in ill fitting housings with wrong length inner pivots and started to
supply a product that is fit for the purpose.
Cheers Matt
Have to agree with the above
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Bluemoon
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| posted on 5/7/10 at 06:24 PM |
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eck home many miles have your done?
The more I see of this (it's happened before with MK bones on this site) the more I think I should do something about it!
I'd be more than happy to pay for a fix, from a manufacture that knows the way to prevent such a failure.
Dan
[Edited on 5/7/10 by Bluemoon]
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Mark Allanson
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| posted on 5/7/10 at 06:26 PM |
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Looking closely at the bush, there is a line through the poly, which might indicate that seamed tube had been used in the manufacture. If the seam had
been at the weld point, this would be a natural shear point.
Any manufacturer using seamed tube needs unauthorised surgery doing on his gentleman bits.
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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zetec
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| posted on 5/7/10 at 06:28 PM |
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Just over 9000 miles over 7 years...
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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Bluemoon
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| posted on 5/7/10 at 06:30 PM |
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quote:
Originally posted by zetec
Just over 9000 miles over 7 years...
eck that's nothing!
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l0rd
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| posted on 5/7/10 at 07:22 PM |
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tilly819 has done a really nice mod on his wishbones for his Haynes Roadster.
I believe he welded a strip of a steel bar around the wishbone tube that holds the bushes.
He might even give some pictures of it.
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t.j.
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| posted on 5/7/10 at 07:28 PM |
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There is a visible "line" on the bush.
So we have a nyloc bushing which is pushing on one point off the welding.
There is also no rubber which can absorb shocks a bit.
I use crush-tubes (peugeot 205) and seamless tube. I hope this won't happen to me.
Please feel free to correct my bad English, i'm still learning. Your Dutch is awfull! :-)
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Andy S
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| posted on 5/7/10 at 07:40 PM |
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Been covered quite a few times in the past this one - and as Matt says - crush tube too short .
Just nice that you are still around to report it.
It's a factor of the leverage applied by the wishbone to the diameter of of the pivot bush - the pivot bolt gets nipped up to high and pinches
and the pivot bush - then its just a matter of time until the required number of cycles has been reached before the failure.
Andrew
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austin man
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| posted on 5/7/10 at 09:01 PM |
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You could have the existing ones modified to take rose joints
Life is like a bowl of fruit, funny how all the weird looking ones are left alone
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procomp
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| posted on 5/7/10 at 11:19 PM |
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Hi
I wouldn't use rod ends on these cars for road use. A decent quality rod end that i personally would be happy to use in the application costs
around £50 + Vat these days.
I use genuine polyurethane bushes in fully adjustable ends that replicate the rod ends for adjustment. The bushes come in 80 85 and 90 shore rating.
End result is high quality bushing in various shore ratings that are self lubricating with stainless inner pivots with CDS outer housings that are
machined to very tight tolerances. Works a dream and last forever with no squeaking. 
Cheers Matt
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flak monkey
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| posted on 6/7/10 at 06:07 AM |
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I can only agree with what Matt is saying.
The failure isnt that uncommon, I have seen at least 3 cars with the same failure, same place and type.
Its a combination of the bush being too tight and the incorrect length crush tube and the weld. Tight bushes will free off over time, mine have, but
they still squeak, I may look into this over the winter. But if the crush tubes are too short the sides of the bush will bind on the suspension
brackets. By being tight there is additional stress put on the tube, right at the weld area which is the worst thin you can do and will always
eventually cause a break at the HAZ.
Seamed tube should have the seam in line with the wishbone tube, if it has then it will be fine.
Sera
http://www.motosera.com
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Steve Hignett
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| posted on 6/7/10 at 06:46 AM |
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Those failures haven't been specific to just the Indy though, other brands have been affected in this way.
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Bluemoon
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| posted on 7/7/10 at 08:05 AM |
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Fished out this other example:
http://www.locostbuilders.co.uk/viewthread.php?tid=121824
Dan
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