Best way to remove an 18mm bolt with stripped head

[AVI_8]

Looking for some advice (again) having just replaced the rear axle on a Fiat 500, that was a battle with rusted fasteners, today I started on what should have been the easy bit, replacing both front suspension arms, after more sheared/rusted fasteners I’ve got everything removed on one side apart from the front 18mm bolt, the bolt head is not accessible with anything other than a socket as it’s hidden by the subframe, got my Milwaukee gun on it with a brand new deep impact socket, hammered the socket in so it was fully seated, thought it was removing the bolt but it was stripping the bolt head instead.
Now I’ve got this

Can’t get to it with any other tools as it’s hidden by the subframe,
Can you guys recommend an extractor for this bolt, I’ve seen these

Bolt Extractor Set, 18 Pieces Impact Bolt & Nut Remover Set, Stripped | eBay UK

Find many great new & used options and get the best deals for Bolt Extractor Set, 18 Pieces Impact Bolt & Nut Remover Set, Stripped at the best online prices at eBay UK! Free delivery for many products!

ebay.us

but it’s a 3/8 drive, I’d prefer a 1/2 drive, and also the sizes for these tools are 17, 11/16 = 17.48, and 19mm, this is (was) an 18mm before I knackered it
Had a same sized seized bolt on the rear subframe, came out with no problem with the gun directly on the socket, in the above case I also used a small extension, surprised the socket slipped as it was hammered tightly on.

 

[Morrisman]

11/16 is about 17.5 I think, a socket may hammer on?

If it will go on firmly try winding back and forth, as if tapping a hole, rather than just screwing out. (Apologies if you’re already well aware of that technique)

 

[AVI_8]

11/16 is about 17.5 I think, a socket may hammer on?

If it will go on firmly try winding back and forth, as if tapping a hole, rather than just screwing out. (Apologies if you’re already well aware of that technique)

Yeh thanks it’s 17.48, I’ll keep looking, if I could get a set with 1/2 drive I’d prefer that, and obviously an 18mm tool, they all seem to go from 17 to 19 though with that 11/16 in between

 

[Nederlands]

Weld a nut on it
The heat wil help

 

[AVI_8]

Managed to find one of those extractors for 18mm and 1/2 drive, if that doesn’t work i’ll try welding a nut with very limited access, nothing to loose as failure will require the whole subframe to be removed.

 

[Dozzer]

My default for thing like this was weld the biggest nut i could find on it, think the heat helps , some freeway or similar penetrating oil
https://www.lsengineers.co.uk/freeway-penetrating-oil-500ml.html

 

[AVI_8]

It’s been slathered in penetrating oil for the past week, don’t think it’s done much.

 

[dieselsamurai]

which ever way you do it heat is your friend with this one

 

[dieselsamurai]

even a gas blow torch and heat it up and let it cool down a few times before you try an extractor

 

[Smallfry]

Prestwick and Fiat. Not a good combo I would think.

Just to be clear, when you say that its "stripped", do you mean the thread is stripped, or the flats on the head, and the bolt has not turned ?

If its the head, MIG weld a bigger nut, plug weld style to the existing head, and fill the centre right up. Hopefully all the heat will free it. It might snap off, but you can repeat. However, try not to accidentally weld the nut/bolt to the subframe.

 

[AVI_8]

Prestwick and Fiat. Not a good combo I would think.

Just to be clear, when you say that its "stripped", do you mean the thread is stripped, or the flats on the head, and the bolt has not turned ?

If its the head, MIG weld a bigger nut, plug weld style to the existing head, and fill the centre right up. Hopefully all the heat will free it. It might snap off, but you can repeat. However, try not to accidentally weld the nut/bolt to the subframe.

It’s the corners of the bolt that have stripped, before that happened, 1400NM of torque from the gun did nothing for a good 5 seconds before it started to turn, I thought it was the bolt turning but it was the socket on the bolt.
Yes @Smallfry every fastener on this car has been fighting me, a 4 hour rear subframe change took days.

even a gas blow torch and heat it up and let it cool down a few times before you try an extractor

I will definately do that but I can only heat the head of the bolt, the captive nut must be welded into the subframe which is hidden inside the subframe. I only have a canister blow torch though.
I dislike fiats now, I’m sure that the fasteners are made from an inferior metal compared to the German cars I’m used to working on, never usually have a problem getting large bolts undone and any small fastener, well I’ve just been cutting them off, and the through bolt holding the ball joint enclosure just snapped with the minimal of torque from a ratchet.

 

[dobbslc]

I dislike fiats now,

Same here!
My son's was a turd of a vehicle, lots going wrong evey couple of weeks, I think I got most of it sorted but we'd had enough and flogged it.
It wasn't rusty though and I got all the front subframe bolts out ok as the last owner had swapped a wishbone but left a bolt loose so I had to strip it all down to check the rest, I found another one loose and the bottom ball joint not fitted into the wishbone fully!

Flimsy plastics, cheap engineering and then add poor maintenance by the previous moron owner and it wasn't a good mix.
He's got a Mini Cooper now and although I don't like BMW's I have to say it's in another league for build quality

 

[AVI_8]

Same here!
My son's was a turd of a vehicle, lots going wrong evey couple of weeks, I think I got most of it sorted but we'd had enough and flogged it.
It wasn't rusty though and I got all the front subframe bolts out ok as the last owner had swapped a wishbone but left a bolt loose so I had to strip it all down to check the rest, I found another one loose and the bottom ball joint not fitted into the wishbone fully!
View attachment 501064View attachment 501065
Flimsy plastics, cheap engineering and then add poor maintenance by the previous moron owner and it wasn't a good mix.
He's got a Mini Cooper now and although I don't like BMW's I have to say it's in another league for build quality

Wow I’m surprised that the through bolt was able to go through without the ball joint not fully seated, bad design, what’s was wrong with a large nut on the top!

 

[AVI_8]

I bought this for my mother in law, only had 50,000 miles, 14 plate, did a full service, new brakes all round, timing belt kit, now it’s got a new rear subframe, very common problem, just needs these control arms done, and hopefully it’ll last another few years.
It’s in cracking condition inside and out, looks pretty new, it’s just when you look underneath it looks as though the previous owner was sponge bob square pants and has lived under the sea.

 

[Smallfry]

I have had a couple of vehicles in the past, admittedly made in the seventies, that crossmember captive nuts either broke free or chassis member gave way.

Ended up having to rebuild some of the chassis. Very off pi**ing and time consuming.

Most chassis bolts seem to be zinc flake coated these days, but one can still have problems.

 

[AVI_8]

I have had a couple of vehicles in the past, admittedly made in the seventies, that crossmember captive nuts either broke free or chassis member gave way.

Ended up having to rebuild some of the chassis. Very off pi**ing and time consuming.

Most chassis bolts seem to be zinc flake coated these days, but one can still have problems.

I’ll keep my fingers crossed that the captive nut holds, my worry is that if a big gun didn’t remove the bolt, it will probably mean that the tool I bought to remove the stripped bolt will not have the grip to get the bolt out with a breaker bar, I’m kicking myself now that I didn’t try the breaker bar first. Lessons learned!

 

[bricol]

I think all your extractor tool will do is put a nice chamfer on the rounded head - I have a set and haven't had too much luck with them.

I never go straight for the impact gun - I want to know that the bolt/nut is turning first. I tell a fib - crank bolt on the Lancia - remembering it's a left hand thread - unlike a guy in the USA who own some monster of an ugga-dugga gun - took the end of the crank off.

 

[AVI_8]

I think all your extractor tool will do is put a nice chamfer on the rounded head - I have a set and haven't had too much luck with them.

I never go straight for the impact gun - I want to know that the bolt/nut is turning first. I tell a fib - crank bolt on the Lancia - remembering it's a left hand thread - unlike a guy in the USA who own some monster of an ugga-dugga gun - took the end of the crank off.

Yes, good advice in hindsight, I’m clearly watching too much you tube.

 

[winchman]

Looking for some advice (again) having just replaced the rear axle on a Fiat 500, that was a battle with rusted fasteners, today I started on what should have been the easy bit, replacing both front suspension arms, after more sheared/rusted fasteners I’ve got everything removed on one side apart from the front 18mm bolt, the bolt head is not accessible with anything other than a socket as it’s hidden by the subframe, got my Milwaukee gun on it with a brand new deep impact socket, hammered the socket in so it was fully seated, thought it was removing the bolt but it was stripping the bolt head instead.
Now I’ve got this View attachment 501004

Can’t get to it with any other tools as it’s hidden by the subframe,
Can you guys recommend an extractor for this bolt, I’ve seen these
View attachment 501007

Bolt Extractor Set, 18 Pieces Impact Bolt & Nut Remover Set, Stripped | eBay UK

Find many great new & used options and get the best deals for Bolt Extractor Set, 18 Pieces Impact Bolt & Nut Remover Set, Stripped at the best online prices at eBay UK! Free delivery for many products!

ebay.us

but it’s a 3/8 drive, I’d prefer a 1/2 drive, and also the sizes for these tools are 17, 11/16 = 17.48, and 19mm, this is (was) an 18mm before I knackered it
Had a same sized seized bolt on the rear subframe, came out with no problem with the gun directly on the socket, in the above case I also used a small extension, surprised the socket slipped as it was hammered tightly on.

Heat is best lots of cycles hot and cold.
These are my Go To for this kind of issue I also few a few different sets some work by drilling a hole in the centre of the bolt
I have also had some success with these

https://www.amazon.co.uk/RIDGID-35585-Extractor-4-inch-2-inch/dp/B000WQYJIG/ref=asc_df_B000WQYJIG?mcid=fe84f5207d7a30b6870a16749fea7df4&th=1&psc=1&tag=googshopuk-21&linkCode=df0&hvadid=697188447825&hvpos=&hvnetw=g&hvrand=841496756990861618&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046510&hvtargid=pla-524848639801&psc=1&hvocijid=841496756990861618-B000WQYJIG-&hvexpln=0&gad_source=1

 

[premmington]

Weld a big nut to it - with a MMA welder - 312 rods the best choice.

And don't ever touch the subframe mount bolts on an old Fiat 500 - they will just snap - I lost count how many I have broken in my workshop.