Propane or MAPP

[Rekusu]

Again, very grateful for your advice. Will try a heat / Plusgas cycle on the thread first and hammer on a smaller socket. I also have an impact driver so perhaps a good hit will release it.

If all fails, I know a local mobile welding expert and could swing by with a suitable bribe!

Will let you know the results

 

[carmanmemoranda]

Is it a pinch bolt with a nut or just a bolt into captive threads ?

What car ?

 

[Rekusu]

Mondeo mk3 from 2003. Rear strut fits into the knuckle and has a pinch bolt that is threaded into a captive thread on one side of the knuckle. Bloody stupid design when a straight nut and bolt would do the same clamping job. It's an M12 so the head is not so large.

Perhaps a stupid question. Most car bolts are heat treated to get max strength during manufacture. If rusted and heat is applied to red hot, then the structure of the bolt (head) will be changed and surely will not take the same torque, leading to shearing. Is that what can happen or not? or is it a case of hopefully it will undo before the shear point?

Just reading something from a Google search, of course the bolt will have had threadlock covering most of its length. Hopefully, it is not rust but just really locked tightly.

 

[Burnerman]

Threadlock can be ferocious in it's grip.......happily though, this is released when heated so no issues with that.
Heating won't affect the bolt's shearing ability, but renew the bolt when you are done.
Are you able to bash another socket on over the rounded head?
John

 

[Stivino]

I would be quite happy for the bolt to shear, I'd just knock it out and put a new one in.

 

[carmanmemoranda]

I would be quite happy for the bolt to shear, I'd just knock it out and put a new one in.

I was thinking similar, but it's in captive threads.

 

[Rekusu]

That is a definitely, not a chance in hell suggestion. It is unfortunately, not a through bolt with a nut on the other side; it's a Ford Mondeo design and that would be too easy.
I
The image shows the problem; on the plus side, I have found that my Irwin bolt extractors are very good at turning a hex head into a circular head! And I have rounded the cutting edge of the extractor.

Have tried heating with a propane/butane torch and all I managed to do was shear the socket adaptor.

 

[Stivino]

Can you get someone too weld a nut onto that?

 

[Burnerman]

At this point, call in your welder pal to weld a nut onto the stub.
If that fails,it looks looks like you’ll need a replacement knuckle.
You could slit the bolt through that slot but of course the remainder of the bolt stays in place.....however it may not be too tight with the head of the bolt gone.
Keep us informed!
John

 

[Burnerman]

Thought number 2.
Cut the bolt away with a splitting disc through the slot in the strut
Grind away the end thread of the bolt that you can see
Drill the old bolt stub out
Replace with a new bolt and nut that passes right through.
John

 

[Rekusu]

Will go the weld route first. Drilling and replacing is definitely a thought but I don't have access to a heavy duty bench drill. Don't fancy trying with my battery drill.

The reason for this replacement is having removed the strut, the rear spring has broken at the top. Based upon the rust, it was quite some time ago. Not good and definitely an MOT fail. I have the shocks. springs and top mount. bump stop and new pinch bolts ready to go.

 

[Burnerman]

I think your hand drill would do ok, with the strut in situ if access is acceptable.
The centre of the stuck bolt would need to be indented with a centre punch and new HSS drill bits used, starting at say 4mm and working upwards.
The bolt won’t necessarily be too hard to drill.....I’ve certainly done a few of these on early Fiestas.
John

 

[Rekusu]

If I cut down the centre and then drilled from the thread end, would only have to go half the distance and with luck, would be able to punch the head end out. Would be nice to keep the thread but a longer M12 and nut would do the trick.

 

[carmanmemoranda]

Will go the weld route first. Drilling and replacing is definitely a thought but I don't have access to a heavy duty bench drill. Don't fancy trying with my battery drill.

The reason for this replacement is having removed the strut, the rear spring has broken at the top. Based upon the rust, it was quite some time ago. Not good and definitely an MOT fail. I have the shocks. springs and top mount. bump stop and new pinch bolts ready to go.

If it's off the car take it to a local engineering place, it will take them minutes, and be much cheaper than coming out to you.

 

[Stivino]

Cutting and drilling would be a last resort for me. If you get a nut welded onto that, it will fall out.