Broken Bolt Question

[Moko]

In typical it's always the easiest bolts that cause the most problems. One of the locating bolts for the anti roll bar bushings head snapped off whilst I was undoing it.

It seems really stuck in the chassis leg but I've tried the double nut trick but the bolt doesn't seem to be the usual M8 thread and the nuts seem to slip or round off. I've tried heating the bolt and that managed a couple of turns and I'm guessing but I would say it's now more than half way out so how do I get it fully out? Obviously I don't want to snap what's left of the bolt and drilling out looks difficult due to the position of the chassis leg (I've removed all the various arms as part of suspension refresh but still not much room to get a drill in )

 

[Nimbus2b]

Try heating it again, apply copious WD40 or similar. Heat again and screw IN a turn or 2. Now heat etc and try to unscrew. Repeat .
Good luck

 

[Moko]

I still haven't managed to get the bolt out despite numerous heating attempts combined with Plus Gas and the internet favourite candle wax. Bought a pair of Irwin vice grips but just cant get the thing to move.

I'm thinking of giving up and getting a garage to have a look at it :dont know:

This raises the next question is it possible to drive the car safely with no rear anti roll bar, or is it best to refix everything and just have three bolts instead of four holding the roll bar bushes in place?

What do you think I should do next?

 

[TonyC911]

Nightmare!

I wonder what our resident mechanic Demort would suggest :dont know:

Is it worth trying an experienced mobile mechanic?

 

[Moko]

It's a nightmare alright and so annoying because I have successfully completed changing all the rear arms despite all four eccentric bolts being fully galvanicly welded in place requiring cutting out with a reciprocating saw.

So the really tough stuff I've managed but one relatively easy bolt head deciding to shear off has stopped me finishing the job.

 

[MisterCorn]

I would put a nut on the end of it, weld the nut on with a MIG welder, and a reasonable chance the heat from that will help to loosen it off.

MC

 

[Moko]

Ok well spent another day trying to get this bolt out, the usual heat, oil etc. But still no luck the thread on the bolt is definitely gone now after trying some more double nut action.

So my dilemma is do I cut the bolt off and try and drill it out and then either re thread it or use a helicoil insert (I've attached some photos to show how much room there is for that option). Not sure if it's possible but might need to cut down the bigger drill bits to fit in the space available. Measuring I reckon there's about 3-4mm still in the chassis leg.

The other option is to take it to a specialist and let them have a go. A local place has quoted £200 to have a go at it. I suppose they could weld a nut to the end of the bolt but only if I don't go with the idea above.

So what do would you guys suggest?

 

[Jam911]

I feel your pain

 

[KarlRS]

997 Bolt

Having done the complete suspension on my own car I feel so, so sorry for you. I too used a reciprocating saw, fortunately only on one of the eccentric bolts, but when fitting New Cross member links one of the bolts snapped upon trying to remove it. Not being funny but it looks as if you have exhausted all options and if someone says they can sort it for £200 in my opinion it is money well spent and saved. I dare not to think what a new subframe would cost then you have all of the other bolts connecting it. How many of those may cause grief! For the sake of £200, I would bite the bullet. Think how much you have saved yourself doing the suspension work yourself!

 

[easternjets]

The only other thing is an Induction heater, they will get the thing glowing in about 30 seconds but it's finding one or knowing someone who has one you could borrow, maybe put something on Facebook seeing if a Mobile mechanic can help.
I take it you can get access from either side, it's not a blind bolt?
If you can get access from the broken side and it has a reasonable flat face and you have a centre punch then start drilling it from the back. Just make sure you are bang on the centre and start with a 2/3 mm bit and work your way up. Buy some fresh bits if yours are a bit dull, it makes all the difference having a sharp drill bit. If your lucky you should be able to drill it without damaging the thread.
If your successful with getting the hole drilled into the bolt, wait till your about 1mm away from the main thread then cut the other side off and it should come out with a bit more drilling.
Good luck, I had a similar thing when I was removing my old exhaust.

 

[Slippydiff]

WD40 is 95% solvent, using it with heat makes for either a great conflagration, or the solvent rapidly evaporating ...
If you can heat the aluminium crossmember (in which the thread has probably galled) whilst chilling the bolt with this :

https://en.foerch.com/chemical-products/technical-chemistry/contact-freezer-spray/freezer-spray

You may get the bolt out.
Failing that, I'd cut the bolt off. There's two trains of thought here.
1. Cut it off flush and you'll be able to establish its centre accurately to centrepunch it, to then drill it out with increasingly bigger drill bits. Or ...

2. Leave something of the bolt protruding so you have something to grip if the drilling process heats the bolt up sufficiently to free it off.

I favour the first option.
The bolts look like M8 diameter, so I'd cut the bolt off all bar the last millimetre, or if you're brave, grind it as close to flush as you dare/to the point the cross section outline of the bolt thread is clear, then use a centre-punch dead centre, and drill through with a brand new 2 or 3mm drill bit, followed by a new 5 or 5.5mm drill bit.
I often find that's sufficient to free off what little there is left of the seized bolt in the hole.
And using a set of picks such as these :

https://www.amazon.co.uk/GTEX-Clean...efix=mechanics+dental+pick+set,aps,75&sr=8-13

You can tease the remainder of the bolts thread portion out in a spiral.

 

[TonyC911]

Is it worth trying some alternative lubricant/penetrating products?

I've heard very good things about 'Bulldog BDX Spray Lubricant' - https://www.carandclassic.com/magazine/bulldog-bdx-product-review/

I typically use 'PlusGas Formula 'A' dismantling lubricant' myself.

Good luck :thumb:

 

[GMG]

...I'd cut it flush and drill it out with decent bits...good luck buddy :thumbs:

 

[Moko]

Thanks for all the replies here's a few answers for the various suggestions.

1. Tried Plus Gas and soaked it for almost a week now daily.
2. Cutting bolt flat seems like a good idea but there's not enough access to what would remain because of the exhaust headers / heat shield.
3. I've tried heating the bolt to cherry red a few times but obviously don't want to heat the aluminium chassis leg as it could warp it but maybe freezing it could work....will investigate.

The only way to drill out the remaining bolt is through the existing hole (car front towards the car back like in the photo I put up). I have some tough 3mm drill bits that I bought when I was trying to drill out exhaust studs on previous 996 and some stubby drill bits one of which is almost the perfect size for the existing hole to act as a guide.

 

[Alex]

They are known as centre drills and used to start a hole off before drilling with a normal drill. If you go down the drilling path, use the ARB bush clamp as your guide by bolting it back on with the other bolt and then use the centre drill to start your hole. Personally I'd just go straight through with a bolt size drill once centre drilled and then get a longer bolt and put a nut on the back to clamp it.

The trick to getting a steel bolt moving in Ally is get the bolt glowing red, then instantly cool with cold water. Keep repeating this process and it'll start loosening up. Obviously its not easy dowsing with cold water but my mechanic managed to get ever single header bolt out my cylinder heads from underneath with this method. You can by freeze spay which would make this process easier to do:

Get yourself down screwfix this afternoon and pick a can of this up:

https://www.screwfix.com/p/arctic-products-crack-it-shock-release-spray-400ml/83415