Rear trailing arm broken bolts, How in trouble am I?? Options

[PaIsa]

Long story short, 2 of the 3 bolts holding the left rear trailing arm broke on me. One broke and left some of the bolt out of the hole so I thought I could get it with heat and vise grip but nope. She is stuck. The other one broke and what is left is in the hole.

I cannot believe I am the first 914 owner dealing with this.

As I said, for the bolt that left me something to work with my plan was to heat it and use vise grip to try to get it. Tried on multiple occasion but she does not want to come out.

For the other one I guess I only have left to dril it out and try to redo the threads hoping for the best.

Does anyone has any other advice or method to try.

I do not have a welding machine so welding a nut is not an option for now and not sure it would work (for the one that sticks out of the hole).

I am open for any advice. I plan to work on this with my son this weekend.

Thanks

[Superhawk996]

You are so (IMG:style_emoticons/default/sheeplove.gif) especially on those that broke off inside the bobbin. I don’t envy you. May God give you lots of courage and patience.

Ninja’s suggestions are solid. Start soaking the fasteners today!

Personally I’d consider hiring someone with a welder to deal with the exposed one.

On the ones broken off under flush - I’d find or fabricate a drill guide to keep any drilling with left hand drill bits centered. I would also pre-grind the underflush fastener as flat as I could get it to prevent the drill tip from waking off center on a jagged - fractured bolt.

Regardless of what happens . . . For the love of God, don’t try to use a bolt extractor

I had one of these come to me pre-broken and with a broken off EZ out in the bolt when I bought my car. I ended up replacing the bobbin during a compete restoration surgery. Details in my build thread if you want a view to the internals of what you’re dealing with. Page 3, post #46. Link to my build in my signature.

I dread thinking about doing this on car & upside down. The saving grace is that Tangerine Racing sells the bobbins if it all goes to (IMG:style_emoticons/default/stromberg.gif) They are weld in and a whole project unto itself . . . But at least they are available vs having to fabricate them from scratch.

Give it your best and if you need clarification on how to make the drill guide, etc. just ask for more clarification.

[JamesM]

You are so (IMG:style_emoticons/default/sheeplove.gif) especially on those that broke off inside the bobbin. I don’t envy you. May God give you lots of courage and patience.

Quit scaring him, its not that bad! (IMG:style_emoticons/default/tongue.gif)

Annoying yes, end of the world, no. Im sure he has much bigger issues with his car, he just doesn't know about them yet.


Pretty much what everyone else said though, soak the crap out of it, get a stud extraction kit and attempt to drill/extract. This can potentially be done from above or below.

Worst case you totally destroy the threads the cylindrical threaded sleeve is just held in with a few welds and can be replaced. Tangerine used to sell these new, not sure if they still do. Even if you destroy just some of the threads its fully threaded longer than the bolt so you can get a slightly longer bolt to grab more threads.

Once you get the bolts out though chase all the threads with a tap and get new bolts, those all look pretty hammered.

[Superhawk996]

You are so (IMG:style_emoticons/default/sheeplove.gif) especially on those that broke off inside the bobbin. I don’t envy you. May God give you lots of courage and patience.

Im sure he has much bigger issues with his car, he just doesn't know about them yet.

(IMG:style_emoticons/default/av-943.gif) imma’ gonna’ steal that line someday.

You are right - not the end of the world just a giant PITA. Bring the patience.

I think Ninja already pointed this out but let me reiterate - the threads are at the top of the bobbins - that is where you want the heat to expand and loosen the threads. Focusing the heat on the bottom where the bolt head is will be less important.