Bonnet pivet woes - advice please

[RichChef]

Hi all,

Recently I removed the bonnet to get better access to the water pump etc... snapped the fg bolt off absolutely flush with the body Attempts to remove it with a set of stud extractors has resulted in the extractor now being snapped off flush with the bolt!

The only way i can see of getting the bolt out requires that i cut a section out of the body... either around the brass fitting (small but hard to set back into the body correctly), inside the wheel arch (would have to be a really bit section to be able to get to the back of the bolt) or a section out of the outside of the wheel arch... any suggestions welcome!

My current plan is to cut the brass fixing out with about an inch around it, remove about half the thickness of GRP from the fixing bit and feather it out from the hole before cutting out some glass mat doughnuts and sticking it all back together again. Is this a realy bad idea?

[pistolar]

A company called "Big Head" do a range of fasteners that are very usefull to TVR cars. They do a plate with a nut which can be pop riveted into place. The nut version is available on a square, rectangular or cicular plate.

Edited by pistolar on Saturday 28th May 20:33

[adam quantrill]

Rich, another approach might be to weld something onto the extractor - like an M8 bolt or something like that. The heat from the welding will go into the brass fitment and it should then start to get a bit loose, and after a while you could probably wobble it about quite a bit then pull it out, but hopefully with much less damage than cutting it out.

Then either GRP another one into place or use Neil's suggestion.

This might have all come about because people have been putting loctite on the bolts to stop them unscrewing. I have a much better solution than this - a locking plate and lockwire through the bolt head. I've had it on for a couple of years and it's completely cured the bolt dropping out (usually at speed - EEK!) problem...

[RichChef]

Adam, I did wonder if it might be a loctite issue as i had been thinking about how i was going to make sure that the bolts didn't undo. Loving your solution i even have a couple of brackets left over from some horn modifications which should be suitable with adaption.

Unfortuntely i don't have access to a welding kit currently. Might be a rent-a-tool job before i start cutting the body (need to fix it before moving house in a couple of weeks, hard to take it for an MoT with the bonnet not connected to the car! ).

Neil, thanks for the link, they look like one to stick in the favourites folder . If it comes to cutting out the old one then i figure one of these will be much easier to graft into the GRP . I also broke a bolt on the back of the dash when i stripped out the interior (managed to make a quick fix for that... temporary is certainly the word for that fix), i can see those coming in useful for that too!

[wooly350i]

Rich,is what you have left to hard to drill out if you can centre punch it first? If you can then use decent drill bits ascending in size until you are close to the thread size then fold the thin remainder of the bolt inwards using a point,perhaps a tap to clean the thread afterwards,best of luck,john.
Ps,have used this method many times in the past.

[adam quantrill]

I don't think he can drill it out as the snapped-off end of the stud extractor is in there and they are very hard. Unless you can get drill bits that are even harder - cobalt perhaps?

[RichChef]

yeah, not a lot is gonna drill through the stud extractor unfortunately i do now wish that i had stopped with that and gone back to the drilling within increasing bit sizes. I had also throught that if i could get the extractor out that i might be able to put a big screw into the resulting hole and try and screw the bolt through the bass fixing, unfortuntaly its well wedged in there.

Instead i shall watch the GP then put the coolant system back together, attach the fan, alternator, radiator, find the fault in the indicator and horn circuit (changed the switch unit so i suspect i know were that problem is ) and give my self a celebratory beer when those are resolved