Audi Q7 3.0 v6 14 snapped stretch bolt

[Richymcc]

Hi just replaced seals on q7 just tightening last strech bolt and snap any ideas how to get bolt out got rocker off number 2 between cams what’s the usual method?

[Olas]

If you’re lucky there might be some of the bolt protruding above the surface which you can get mole grips on to and turn it out that way

Other option is to carefully weld a washer to the bit of bolt you can see, weld a nut to the washer and turn it out that way.

Some people believe in left handed dill bits and/or easy-outs - personally I’ve seen them do more damage than good.

Last resort is to have it towed to a garage - they do it every day.

[Olas]

Head bolts or cam cover bolts?

[Richymcc]

Injector bolt there is a couple of mm showing

[ChampionRabbit]

Torqued enough to snap the head off, I doubt mole grips will take it off. More successful that reverse thread drills in our workshop tends to be drilling the middle and hammering a torx bit in. Ymmv.

[Olas]

Gently warm the surrounding area and get a tight grip on the bit sticking out - it can work and is worth a try.

Cutting a slot into it and using a screwdriver can work.

With a stub that stands proud of the surface, welding is your best bet.

[finlo]

If the head has sheared there shouldn't be any tension on the remnant.

[mickyh7]

finlo said:

If the head has sheared there shouldn't be any tension on the remnant.

Tourque stretches the threaded section!
Your way of thinking would be to Chisel the Head off a stuck bolt, then remove the remaining stud bar with fingertips or Bluetac !
Engineering is not this simple!

[Olas]

mickyh7 said:

Tourque stretches the threaded section!
Your way of thinking would be to Chisel the Head off a stuck bolt, then remove the remaining stud bar with fingertips or Bluetac !
Engineering is not this simple!

The head stays in place and the thread works it’s way down the hole, creating tension.

When the head (or stopper) is no longer there tension is reduced although not eliminated because the fixed end (anchor point) is no longer there. Open va blind hole makes a difference too.

What approaches have you tried so far?

[rash_decision]

Get a 5mm drill and sharpen it with a reverse/counter clockwise flute on it. Get a drill that goes into reverse. Put a nice centre punch right in the middle of the snapped bolt and drill it in reverse. I have now removed 3 in this way. As the drill bites, it will screw the remaining threaded part out the head. They’re only torqued to 6nm plus 90 degrees but with the bold head sheared there will be no resistance.

Just have a magnet ready to recover the broken part from the cam area!

[paintman]

mickyh7 said:

finlo said:

If the head has sheared there shouldn't be any tension on the remnant.

Tourque stretches the threaded section!
Your way of thinking would be to Chisel the Head off a stuck bolt, then remove the remaining stud bar with fingertips or Bluetac !
Engineering is not this simple!

That actually works quite well although I prefer a drill! I've drilled the heads off a number of bolts which have been rounded off & then used a centre punch & left hand drill bit.
I'm not a fan of the eezi-out as I've seen too many broken in drilled bolts which have then needed spark erosion.
Or a small drill with fine bits to make a slot in the remaining 'stud bar' to suit a screwdriver. First did that years ago getting the remains of sheared studs out of BSA bike engines.

Local engineering company used this type to remove a sheared bolt which left a sticking out bit from an ally head for me a couple of years ago. Never seen them before & using the remains were drilled absolutely dead centre.
https://www.ebay.co.uk/itm/US-Pro-25pc-SCREW-EXTRA...
This was about the best I could find with a quick google: https://www.youtube.com/watch?v=bR_kfdtuelU

Edited by paintman on Wednesday 26th February 01:48

[rev-erend]

One other option is to centre punch off centre and then lightly hammer and push anti clock with the punch tool.

Naturally once removed you should measure the depth of this vs others and possibly retap if needed.