Bolt extraction from Aluminum LCA
#1
Bolt extraction from Aluminum LCA
Well I have finally got the time now to attempt this.
So what way should I go about removing these?
rear sway bar 13mm bolts for the endlink mounts to the LCA(Aluminum)
So what way should I go about removing these?
rear sway bar 13mm bolts for the endlink mounts to the LCA(Aluminum)
#3
Re: Bolt extraction from Aluminum LCA
I take it you're trying to remove the broken bolt? (I see now)
Get a small center punch and you can turn the broken bolt out by placing the point of the punch near the edge of the bolt and lightly tapping the bolt counterclockwise. Take your time and it will eventually turn all the way out. If you hit it too hard you will distort the threads. If that happens you will need to drill a center hole in the bolt and use an EZ out to turn the bolt.
Get a small center punch and you can turn the broken bolt out by placing the point of the punch near the edge of the bolt and lightly tapping the bolt counterclockwise. Take your time and it will eventually turn all the way out. If you hit it too hard you will distort the threads. If that happens you will need to drill a center hole in the bolt and use an EZ out to turn the bolt.
Last edited by DOOM; 01-27-2015 at 02:34 PM.
#8
Re: Bolt extraction from Aluminum LCA
First of all, are those bolts or studs, and is it a blind hole or through hole? They look pretty clean, so this might not super difficult to remove.
The solution depends a lot on what the problem is though.
If the bolt was overtightened but is fairly clean etc., and you broke the head off trying to remove it, there shouldn't be much preload left on the threads (except for thread distortion) because the head is now missing. In this case the radial tapping with a centerpunch method may work, or an EZ-Out. Use penetrating oil to help lubricate things.
If the bolt is seized because of galling or corrosion, you've still got the same problem that needed enough force to break the bolt head in the first place. You're going to need something that can apply a lot of force in a small area, like heating the bolt. The expansion forces from heating are huge, and hopefully will shear the layer of corrosion/scale between the bolt and the aluminum.
I don't like EZ-Outs because they like to break, and they only work for certain types of jobs. You can't usually apply much more force with an EZ-Out than you could when breaking the bolt head off. If the threads are seized, an EZ Out isn't going to do a damn thing. If you heat the bolt (or penetrating oil has freed things up), and now it's pretty well broken free from corrosion, the EZ-Out can help get it out.
You can also drill out the bolt with a drill press, or take it to a machine shop (preferred for best results) to have it drilled or plunge-milled out, then you can peel/pick the bolt threads out of the hole. It's pretty easy to drill it out when it's fixtured properly to a machine table so things aren't moving around and you can find the hole center properly.
If all else fails, you can likely find a machine shop with an EDM machine to erode the bolt for you. Not cheap, but not that bad either. Expect maybe $50-100 per bolt for EDM removal. Might be cheaper to buy another control arm at that point, depending on what the used parts market looks like for that car.
Welding a new head/bar/tab/whatever onto the bolt is a strange thing. I've seen it work, but you have to be a good welder to make it effective and to not damage the aluminum. I actually think that the welding heat helps things out a little bit as well, so it may be a combination of heat and also having a new bolt head.
The solution depends a lot on what the problem is though.
If the bolt was overtightened but is fairly clean etc., and you broke the head off trying to remove it, there shouldn't be much preload left on the threads (except for thread distortion) because the head is now missing. In this case the radial tapping with a centerpunch method may work, or an EZ-Out. Use penetrating oil to help lubricate things.
If the bolt is seized because of galling or corrosion, you've still got the same problem that needed enough force to break the bolt head in the first place. You're going to need something that can apply a lot of force in a small area, like heating the bolt. The expansion forces from heating are huge, and hopefully will shear the layer of corrosion/scale between the bolt and the aluminum.
I don't like EZ-Outs because they like to break, and they only work for certain types of jobs. You can't usually apply much more force with an EZ-Out than you could when breaking the bolt head off. If the threads are seized, an EZ Out isn't going to do a damn thing. If you heat the bolt (or penetrating oil has freed things up), and now it's pretty well broken free from corrosion, the EZ-Out can help get it out.
You can also drill out the bolt with a drill press, or take it to a machine shop (preferred for best results) to have it drilled or plunge-milled out, then you can peel/pick the bolt threads out of the hole. It's pretty easy to drill it out when it's fixtured properly to a machine table so things aren't moving around and you can find the hole center properly.
If all else fails, you can likely find a machine shop with an EDM machine to erode the bolt for you. Not cheap, but not that bad either. Expect maybe $50-100 per bolt for EDM removal. Might be cheaper to buy another control arm at that point, depending on what the used parts market looks like for that car.
Welding a new head/bar/tab/whatever onto the bolt is a strange thing. I've seen it work, but you have to be a good welder to make it effective and to not damage the aluminum. I actually think that the welding heat helps things out a little bit as well, so it may be a combination of heat and also having a new bolt head.