sheared subframe bolt '96 850

Post by **volvolugnut** » 23 Dec 2020, 13:37

I can't address your other questions, but left hand drill bits will make holes just as well as right hand bits made of the same material. I hope you purchased quality bits. Bits marked HHS for High Speed Steel would be the minimum specification. Try to lubricate and cool the bits with oil while drilling. If they get dull change bits to the next larger size sharpen the bit just like a right hand bit.
volvolugnut

jlp920 · Post by **jlp920** » 24 Dec 2020, 13:58

volvolugnut wrote: 23 Dec 2020, 13:37 I can't address your other questions, but left hand drill bits will make holes just as well as right hand bits made of the same material. I hope you purchased quality bits. Bits marked HHS for High Speed Steel would be the minimum specification. Try to lubricate and cool the bits with oil while drilling. If they get dull change bits to the next larger size sharpen the bit just like a right hand bit.
volvolugnut

That's helpful, thank you. I did get HHS bits that seemed like good quality.

Post by **cuhfs** » 24 Dec 2020, 14:43

I had this happen on a left front subframe bolt once it was 100% IMPOSSIBLE to extract. I used the best tools and equipment available. IT would not extract. It would not drill out. Could not break it apart. Tight spot.... sheared bolt would not move no way no how. My solution was that I had an Really good WELDER weld in a threaded Stud. Hope this helps someone.

Post by **xHeart** » 25 Dec 2020, 08:32

jlp920 wrote: 23 Dec 2020, 10:04 I remain grateful for your help.
I'm concerned about staying true with the bolt for the whole 50mm I will need to drill.
I'm also wondering about the effectiveness of using left hand bits for the whole process. Will they drill as well as regular bits?
Another question is the material I'm drilling into, what the inside of the frame looks like there...
is there room for error in case a re-tap is needed? My concern with drilling through the bushing is staying true in the bolt hole. I feel as though I'd be flying a little blind, so I'm leaning toward dropping the subframe. Thanks again for helping me to work through this, I'm still piecing it together through
all the suggestions I've received so far.

volvolugnut's procedure is spot on -- hollow out one mm at a time.
You're between a rock and a hard place. You'll know the level of difficulty in first 10 minutes of actual drilling.

Broken bolt length can be misleading. Compare it with the depth of the female thread on the good side to determine the actual length of task at hand.

jlp920 · Post by **jlp920** » 29 Dec 2020, 10:24

I started digging into the sheared off bolt with my new HSS left hand bits, just to see what I'm up against.
the bolt is actually not bad for drilling

: IMG_8389.jpg (17.8 KiB) Viewed 1527 times

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sharpen the bit just like a right hand bit.

How does one sharpen a drill bit? Never done it.

Post by **volvolugnut** » 29 Dec 2020, 12:47

Here is a good YouTube video on bit sharpening.
https://www.youtube.com/watch?v=uqPgdEThQzc

It takes some practice to do it well. Good news is you have a very long bit that is all the same shape and you can try to sharpen many times until you get it right. Just try not to get the bit very hot (bluing).

volvolugnut

Post by **RickHaleParker** » 29 Dec 2020, 13:00

volvolugnut wrote: 29 Dec 2020, 12:47 Just try not to get the bit very hot (bluing).

The heat is easy to manage. Grind for 5 seconds then dip in Ice Water. Grind dip grind dip ....
Sharp point, with equal widths on either side. Do not change the angle of the point.

If you flat out ruin a tip you can cut it off with a Dremel and grind a new point. Make sure you get the new points angle correct.

Post by **j-dawg** » 30 Dec 2020, 01:12

volvolugnut wrote: 29 Dec 2020, 12:47 Here is a good YouTube video on bit sharpening.
https://www.youtube.com/watch?v=uqPgdEThQzc

It takes some practice to do it well. Good news is you have a very long bit that is all the same shape and you can try to sharpen many times until you get it right. Just try not to get the bit very hot (bluing).

volvolugnut

Another cool video about drill bits:

Skip to about thirty seconds in, and then budget thirty minutes 'cause it's a great video. The author makes a simple drill bit while explaining how a drill bit actually works. Not great as an instructional video for grinding them, but extra great if you just wanna learn more about drill bits!

Post by **abscate** » 30 Dec 2020, 05:16

Perfect application for your newly arrived Christmas present of a Dremel too and the 6700 drill guide ( I think)

Post by **volvolugnut** » 30 Dec 2020, 12:56

If you have lots of drill bits to sharpen, consider the Drill Doctor product. It is fast and easy. Google it.
volvolugnut