Captive nut in suspension mounting bracket

[dmccormick]

My 1996 A4 just failed its MOT on the front upper ball joints, both sides. Decided to have a go myself despite ominous warnings about the infamous "pinch bolts" that drive people mad.

Anyway, pinch bolts were OK with a breaker bar and some penetrating oil. However, on A4 you have to take the suspension strut out to get the track arms off. This requires removing three screws that go from engine bay into a bracket that holds the strut and spring.

Unfortunately these bolts were not so kind. On one side the bolt head sheared off. This not so bad as at least I can get the assembly out and try to drill the bolt out.

However, on the other side the captive nut in the bracket broke loose. I used a Dremel to cut the bolt head off so I could get the assembly out. Am now wondering what to do. If you see picture you can see the captive nut and the hole where it is supposed to go.

I looked on an ETKA and it doesn't seem this captive nut is a part, I guess it is integral to the bracket. I was wondering what to do and hoping for some advice here.

Is this a good excuse to treat myseld to a MIG welder and try to weld the nut back into the bracket (assuming I can drill out the bolt first). Or is this a bad job and I need a new bracket ?

Another question if I may as well - GSF car parts sell the track arms at £25 each. However, on ebay I see a 12 piece arm kit for £120. Anyone any experience of these kits - is the quality OK ?

 

[Mursal]

Put the nut in a vice and a bit of heat on the nut and thread the broken bolt out with a pair of vice-grips. Failing the availability of heat, you could try drilling out the broken bolt which wont be easy with such a light wall nut. Putting a new bolt and nylock nut down through the old nut, if you have the room underneath?

Local breaker might still be open for good nuts?

 

[dmccormick]

I think the issue will be that you have to put the track arms into the bracket before remounting and the track arm covers over where the nut would be. I think I wouldn't be able to get a spanner or anyhting to grip the nut whilst trying to fit the bolt.

Maybe a washer that has jagged edges that would grip the nut and bracket and then pull up on the bolt whilst tightening it ?

 

[Nozzle]

Welding it is your best bed (providing you can do a good job). Get rid of all the rust before welding, and don't waste your time with a gas-less set up. Get the new nut aligned, (if it's zinc plated, grind that back to bare metal) then tack weld and allow to cool - make some adjustments as required. While you're welding, best to have a bolt in the nut as then an spatter generated will be prevented from crapping up the threads.

Nozzle

 

[dmccormick]

Great. Really I just wanted someone to tell me to get a welding kit
Have wanted to for a while and my 9 yr old son expects me to be building all kinds of gadgets if I do.

Am I right in thinking that a MIG welder is the way to go for a complete novice and this kind of job ?

 

[AlanE]

But whatever you do get some scrap bit of metal and practice first.

 

[GasBod]

Ebay is cheapest bet.

 

[JulianP]

You just need a suitable nut and bolt and a thick washer under the strut tower top - you'll be able to hold it with an open ender while tightening from above.

 

[Dave54]

If you're after a mig machine it might be worth having a look here first
http://www.mig-welding.co.uk/buying.htm
(no connection)
There's a shop there to buy welders, but the forum and advice are independent.
The guide at least tells you what to avoid in a welder.
You'll end up spending more than you first thought!

 

[Belle427]

if you dont think a nut will be accessible then welding is your only option, seems a lot to spend on a mig though just for one job.
Maybe worth chucking a local garage/engineering workshop a tenner to mig them on for you.

 

[dmccormick]

Thanks for all advice. Yes expensive to get a MIG just for this, but there have been a few times where I could have done with one in the past so thinking about it a bit more.

I've read a lot on the welding forum and realise it's not easy or quick to learn to weld, so i might get a local garage to do it anyway while I mull over doing a welding course locally first.

 

[mfarrow]

Yup I've dabbled with my welder but would not yet think I'm at the stage where I can use it in anger on a car body.

It's a useful tool to have about though for odd jobs, fabricating parts etc.

 

[JulianP]

Thanks for all advice. Yes expensive to get a MIG just for this, but there have been a few times where I could have done with one in the past so thinking about it a bit more.

I've read a lot on the welding forum and realise it's not easy or quick to learn to weld, so i might get a local garage to do it anyway while I mull over doing a welding course locally first.

It's a captive nut - the weld will just be to keep it in place, it does not contribute to the integrity of the assembly. You could use epoxy glue if you wanted! But as I said previously, just use a nut and bolt as the factory only use captive nuts to hasten and simplify assembly on the line.

Either a nut and bolt or any old sparrow sh1te welding will suffice, providing you keep the weld away from the threads

 

[greasedmonkey]

If you want to just sort out a captive but, get yourself a 35 quid arc welder as the weld you put on won't be doing anything once it's all assembled. If you want to do more welding, and maybe venture into fabrication and repairs, a good mig is worth every penny.

I have been welding for 25 years and can say it is incredibly easy to stick two bits of metal together, it's very difficult to do a good weld without knowledge and practise.

 

[dmccormick]

I decided to treat myself to a MAP torch and bench vice (black and decker workmate not up to gripping the nut whilst being torched I think). And after getting the net red hot it was actually quite easy to unscrew the stud.

Wife is not too happy about the vice on the kitchen worktop though

Re the captive nut and whether just to use a normal nut and spanner, this is the access and I don't fancy getting a spanner on that.

Especially not if I need to undo it after a year or so - the existing bolts sheared off not right at the start but half way through undoing them so the nut needs to be held in place not just for the tightening but all the way.

Given I've got the MAP torch now, I was wondering to try brazing it. Do you think it would work, or better to get a cheap arc welder ?