Suspension: Broken Subframe Bolt

[nu11eaf]

Spotted these broken screw removers in Aldi today, they are cheap enough to buy just in case needed. They screw in and grip anti clockwise. Could be used for broken bolts as well, if bolt drilled.
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[Clan]

Originally Posted by nu11eaf

Spotted these broken screw removers in Aldi today, they are cheap enough to buy just in case needed. They screw in and grip anti clockwise. Could be used for broken bolts as well, if bolt drilled.
Attachment 113970
Attachment 113971

why did the bolt break? did you apply so much massive torque with a long bar and the thread was seized so that the bolt sheared ? If so , no extractor will get it out unless you heat up the nut within the chassis . remember you will have to put a lot more torque through the extractor than the big bolt head would allow so the extractor will break off in the remains of the bolt and you won't even be able to drill it out then .

[AidXC90]

Originally Posted by Clan

why did the bolt break? did you apply so much massive torque with a long bar and the thread was seized so that the bolt sheared ? If so , no extractor will get it out unless you heat up the nut within the chassis . remember you will have to put a lot more torque through the extractor than the big bolt head would allow so the extractor will break off in the remains of the bolt and you won't even be able to drill it out then .

Hi Clan,

Yes, I sheared off the head with a breaker bar. The three other subframe bolts came out easily after using the same breaker bar, so I had no reason to think the passenger's side front one would be any different.
However, there is no nut within the chassis in this situation. Instead, the bolt screws into a threaded sleeve or tube, the lower end of which forms the subframe bushing locator spigot, while the far end of the sleeve protrudes about half a centimetre above the chassis metal. The bolt's tip sits slightly recessed in this sleeve and together they form a little pond of moisture inside the chassis which rusted the bolt from the end downwards. I still can't attach pictures but when I am able to, all will become clear. .

It's very difficult to get to that end of the bolt, but I did manage to soak it in Plusgas several days ago and I can only hope it's worked its magic in the meantime. The subframe bushing locator spigot surrounding the bolt from below the car is flush with the sheared end of the bolt. I may be able to get a small kitchen blowtorch flame in to heat up the rusted end in the chassis as I think that's where the trouble started with the rust. I'll try that today. The extractors arrived yesterday but I agree that they also might fail. I watched a video on YouTube yesterday where just such an extractor snapped twice, so they are not necessrily the panacea I'd like them to be. I have to drill out the hole one more time to accomodate the extractor anyway, and if it fails to move the bolt with a fair amont of force, I'll stop using it and resume drilling the bolt to try and weaken it enough to get it out by destruction without damaging the hole's threads. That's all I can do.

I'm not in a happy frame of mind right now, but short of reassembling the subframe, steering rack, discs, pads, ball-joints, hub bearings, and control arms then taking it to a garage to have them drop the subframe again and tap the hole, I have no option. I may have to do that anyway but I owe it to myself to give it one last go.

[AidXC90]

Originally Posted by nu11eaf

Spotted these broken screw removers in Aldi today, they are cheap enough to buy just in case needed. They screw in and grip anti clockwise. Could be used for broken bolts as well, if bolt drilled.
Attachment 113970
Attachment 113971

Thanks for the help nu11eaf, but the two different types of extractors I have now are more robust than these. I hope to upload some pictures of the whole thing when I find out why I can no longer post pictures. But see my reply to Clan's post for an update on extractors etc.

Thanks again for trying to help. It's a really good forum because people are so willing to help and pitch in with ideas to assist members who are stuck.

Aidan

[Clan]

yes I called the tubular nut a nut :-)
there should be locktite on the old bolts , which will stop water going all the way into the thread , heat melts the locktite and eases things as well as the expansion but you will need a proper oxy-acetenyl flame ..

[Bob Meadows]

Aidan: ~ after the extractors are locked in place ( I believe the type you have are held tight- parallel) it is better to try removal by initially rocking the same i.e. left—right in small amounts rather than a major push/pull, once you detect movement keep rocking it out until you are sure it will come away.

Want to borrow a Tap? Plenty here but would be Imperial (no metric) but a suitable bolt would not be a problem.
Regards Bob

[IainG]

Hi
The other problem with some extractors, as they are tapered, the more force you apply to the extractor the more it expands the bolt and makes it tighter in the thread. We used to use a hex extractor that hamered in to the drilled hole. Like a cut off Allen key. We found these gave a good rotational force without expanding the bolt too much. And you can turn either way, sometimes it is easier to let the sheared bolt carry on through the hole. Also if it moves a bit you can work it backwards and forwards with penetrating oil to free it up

Similar to these, but they were hex shaped as opposed to spline

https://www.google.co.uk/search?q=he...UKtVbhiEPflgM:

Iain

[AidXC90]

Thank you to all the members who have advised me and tried to help but I think I've really hit the wall now.
I finished drilling through the bolt this morning, but before I got all the way through, I noticed the colour of the fluid exiting the hole changed to a rusty brown. I thought this might have been because the drill bit was overheating, which it was, so I changed to a new 9mm bit and proceeded.
I did drill through to the end of the bolt but it seems I was not drilling perfetly straight, no surprise there , and somewhere up towards the top I must have drilled throught the side of the bolt and into the hole's threads. That broke the dam and it must have been the rusty Plusgas flowing out of the bolt hole via the drilled hole inside the bolt.
I did try the extractor and it worked to an extent in that about 3cm of bolt came out - see pics - after snapping off from the remaining 4cm which is still lodged securely in the now buggered hole. I don't think drilling an even bigger hole will help so I presume the only option now is to reassemble the car and take it slowly to a pro to get them to drop the subframe again, finish the extraction and re-tap the hole?

I'm am not a happy person

[AidXC90]

Forgot to mention that after I removed the 3cm portion of the bolt, I did reinsert the extractor and tried to move the remaining portion but it didn't want to budge so I stopped trying to force it in case the extractor snapped off in the hole. I've been in touch with my local Volvo dealership to see if they can remove the bolt and tap the hole.

[luggsey]

Have you tried running a new bolt up there to see if it snags the edge of the bolt that's left and drives it out?
Not much to lose now?