I would replace the entire trailing arm. Then you will have a piece of mind.

Also as part of my regular work on the car now, I retorque the suspension bolts.

 

Is your bolt stuck or spinning?

Mine was spinning but could not be backed out and the aluminium threads on the trailing arm was stripped and loose. Likely cross threaded during the install? Or could be that the stresses I put on it pulled it out and stripped the threads. I like to oversteer on the track.

 

Mine is entirely stuck, not spinning at all.. 200 ft-lb of torque won't even make it budge.

 

Pm nintentom. I think he managed to find the trailing arm in the $380 plus minus range if my memory is right.

 

I've been working at it and managed to get the drill this far in. I followed earlier advice and let the drill bit cool down, add oil, and then try again. It seems to be working, slowly but surely. So let's say i did end up drilling through all the way- then what?

 

once you get all the way thru, get the next size up bit (or two) and drill again. You're now just removing more and more from the inside of the bolt. Eventually the remains should just crumble or at least collapse enuf to be easily removed. (keep trying the easy outs too) HOPEFULLY this happens b4 you get too near the threads. The then check the threads carefully for damage and if they look salvageable get a GOOD tap set and chase the threads. That is run a tap thru them to clean up any bumps you may have introduced.

BUT if you find the threads have been damaged because the bolt you are removing was cross threaded ..... well you might want to talk to the one who installed your dampers.

 

If they are damaged beyond repair, what about a helicoil set?

 

I've never had to use one so don't feel qualified to advise you about helic'

 

I would say that you have one more possibility. I have used a Dremel to grind a slot in the exposed end of the bolt. Make it deep and just wide enough to put the biggest flat blade screw driver you can find in it... then put a little heat one the aluminum using a MAPP gas torch. You don't want to put too much heat on it and anneal (soften) metal. Put an adjustable wrench on the screwdriver to help turn it, Pray a little and then twist like crazy. The heat should help loosen it up. Good luck with it.

 

When you drill that hole all the way through, just call that your pilot hole. Then you need to attack it with a drill bit that will wipe the whole bolt out. Looks like you'll be investing in a drill bit sharpener for the garage! You're destined for a replacement bolt and nut setup. It will work fine. Plenty of people have done it on Motoring 8lliance.

 

This will be the death of me, I swear....... I am drilling from both sides (alternating) in what appears to be the dead center, and I have gotten the hole past the point where they should be connected and therefor making a hole all the way through- but no such luck! I am still just drilling infinitely and it is taking FOREVER with what seems to be no end.

Do you have any links to the threads where people have had this problem before? It might make me feel better about my situation.....
(can you tell I'm going crazy?)

 

RedAndBlackMiniS
I am not sure what type of drill bits you are working with but this should not be as difficult as it sounds. I would look for higher quality bits, or go to cobalt bits which will withstand heat better. Get the drill speed correct and you should be able to drill thru without much difficulty. Sounds to me that you have some cheap bits that are dulling almost immediately.
Steve

 

Use high end cobalt drills

 

And learn that speed is not your friend. At this point you have killed that drill bit. Drill slowly (the smaller the bit the faster you can drill, but I'm talking <1000rpm), and use oil, and a sharp bit.

 

Google this...

"trailing arm stripped bolt hole Motoring 8lliance"

Replace the '8' with 'A'. This site blocks any mention of the website for some stupid reason. Very childish in my opinion.

 

Okay, guys. I'm off to home depot to get some cobalt drill bits. Hopefully this works.

 

I bought a torch as well as a 14-piece cobalt drill set. How can I use the torch to my advantage in this situation?

 

I got it through! Those cobalt drill bits went through like freaking butter, I wish I had used those all along! It has drilled through 2 holes- I tried to go in from both sides of the bolt and the holes ended up in different places, which adds a little bit extra of a challenge. Hopefully I can get the two holes connected and it'll be all good.

So I am just going to keep drilling bigger and bigger until it fills the entire hole? Then put the bolt/nut mod in?

 

At this point I would heat the aluminum under where the bolt goes through. That should expand the aluminum a little to help loosen the bolt. Then while it is still really hot try the easy out. It would be good to try to save the threads. If that still doesn't work then try the nut and bolt. Use a good quality Grade 8 bolt for these as that is the strongest.

If you save the thread, use a replacement MINI bolt and lubrecate the threads. This is necessary to load the shock in that socket.

 

I'd try to use the extractor, you may be able to turn out the remains .... if it does not work, drill slightly larger, then try again. Eventually the sides of the bolt are going to loosen ... or they should anyway.

This way is an attempt to save the receiver threads - to be inspected and chased so you can possibly use the factory threaded bolt....

Or you can jump to where you'll end up if the threads are trashed: keep drilling until you get a smooth hole thru the arm - then grind as needed to get a flat mating surface on the back side (according to other posts here that is needed) and use a bolt and a nut in place of the bolt threaded into the part, as described by others. (you'd really want a smooth shank bolt with no slop thru the hole then on the back side a washer and then a nylox nut. I'd use all stainless.

editorial comment: from the pictures you gots a real mess there . . . if this is not a cross thread issue that's destroyed the receiver threads I owe someone a donut. I haven't experienced anything like that, even on my 66 Mustang or 79 Mini

*******

note to readers - there is a lesson here . . .

there are times when you really need to pay for the GOOD tool. Drill bits thru wood - you can get away with cheap stuff; thru hardened steel? You BETTER pay for the good stuff. Had the same issue with the guy across the street who was trying to drill out a bolt on his Jeep. Insisted his bit was good quality but was getting no where. Finally (to humor me) he went to HD and got a GOOD drill bit. Job was done in 5 minutes.

 

There is no way that easy-out or my grab-it is getting that bolt out. I tried heating it and then using pliers to slowly turn it while it was in there, and it goes nowhere. I can't seem to make the hole any bigger even with trying new bits. There is a hole through drilled through the bolt... I'm wondering if there is a grade 8 smaller bolt I can run through the hole I've created and then put a nut at the end of it to secure it?? Does this sound plausible?

 

If you put a smaller bolt in, it will fail faster than the original did. Even if the original was only grade 5 (and I'm not sure why it would be), the thickness of a fastener contributes a whole lot to its strength.

Keep drilling. Or just replace the part.

 

I would never feel comfortable making this work. IMO I would call around places like http://www.miniworldinc.com/ and see if they have a used one. You spent money already, when IMO you should of used that money on a replacement. Just my opinion.

 

Braminator... I'm a poor college student and don't have $400 laying around...

Anyways, managed to get this far. Honestly this is the most tedious thing I've ever done...

I plan to get the long bolt with the nut on the end when this is over and done and then call it a day.

 

I hear ya and feel your pain.