A little knoweledge is definatly dangerous

A little knoweledge is definatly dangerous

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77racing

Original Poster:

3,346 posts

187 months

Thursday 23rd October 2014
quotequote all
I have often heard that saying over the last 50 years off and on but not fully understanding why that would ever apply to me. I DO NOW.

I had a little off in my Tuscan and it needs a new lower suspension arm .While I was replacing the arm I thought I would replace the rose joints as well as they had taken quite a shock through them. I bought a new arm and spent several hours sanding and painting it up and it looked superb even if I say so myself. Feeling rather buoyed by how well it was all going I thought I would put in the new top of the line rose joints and get the arm etc back on so the car could have all the geo set up on it at my local garage.That's where it all went horribly wrong, first rose joint just screwed in ok into the arm, end socket and I thought how easy was that so I started screwing in the second rose joint. It was a little stiff to start with no more so than the first then it got a little harder so I thought I would just use a spanner to help screw it in a bit further. The enlightened of you will now be saying what a plonker and the unenlightened such as myself will be thinking so what just give it a little more persuasion.I thought to myself this don't feel right so I will take it back out and see what's what. As I tried to unscrew it, it just would not budge any which way not in a vice with a huge spanner on it not forward or back. I have never come across this phenomenon before it's called cold welded. I had basically cold welded my shiny new rose joint into my shiny new lower arm. Off to my local garage who had to put heat onto my lovely shiny lower arm with an acetylene torch, that's burning off my paintwork, to a lay man. As they were unscrewing the joint out it decided to break half the threaded shaft off in the arm socket. Now it is at my local engineering company to see if they can drill it out at £50 an hour labour, he thinks it will be about an hours job.If it won't drill out ok, I will have to buy another new arm at £190 because he won't Helicoil a suspension arm and a new rose joint at £12 total £202 repaint it all add that to the initial purchase of £202.That all adds up to me just going out side now to open my wallet in the high street pull my trousers down and just throw the whole contents of my wallet into the gail force wind to see what that feels like instead. Cold welding WTF !!!!!

My new arm having heat added.....



The remains of the rose joint shaft in the socket...........




jamieduff1981

8,025 posts

140 months

Thursday 23rd October 2014
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What a bummer. I take it the threads were just a touch to snug and generated some friction as you screwed it in?

macdeb

8,510 posts

255 months

Thursday 23rd October 2014
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Firstly I have to admire your honesty, and secondly a thank you in being so as to prevent others from doing the same sort of thing clap

phazed

21,844 posts

204 months

Thursday 23rd October 2014
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Ah, Perry, Perry, Perry.

As Mac said above and maybe, "stick to driving" wink

We feel the pain in your wallet!

steve320ise

159 posts

143 months

Thursday 23rd October 2014
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Lubrication can be a wonderful thing, learning from our mistakes is not all bad when you share cos we all make them, thanks

Llanelli-Rob

533 posts

224 months

Thursday 23rd October 2014
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A very common problem when in comes to threaded stainless fastners I'm afraid, also called thread galling....lube is the answer and if it don't feel right don't force it.
Rob.

hidetheelephants

24,349 posts

193 months

Thursday 23rd October 2014
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Not sure why he won't helicoil it; many aeroplanes are held together by large numbers of helicoiled threads, it generally isn't a cause of aircrashes.

phillpot

17,116 posts

183 months

Thursday 23rd October 2014
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That should drill out an re-tap I'd have thought?


If not can't they cut it out and weld something like this back in?



On the other hand at their labour rates with no guarantee of success perhaps cut your losses and get a new wishbone!

phazed

21,844 posts

204 months

Thursday 23rd October 2014
quotequote all
hidetheelephants said:
it generally isn't a cause of aircrashes.
That's reassuring then laughlaugh