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Like A Bawwsss
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25,247 Posts
Discussion Starter · #1 ·
Hi

I have 1/2 a bolt in my gearbox so going to drill it out and re-tap the hole.

ETKA lists the bolts as a M10 x 70 x 32 for the rear bolt on gearbox.

So what size drill bit do I need to drill it out. Am i right in thinking it will be a 10mm drill bit and tap to suit? But if i tap a 10mm hole...then wont it be the wrong size to put the bolt it?

So can someone please advise what I would need to do to get the bolt out. Do i drill it out at 9mm and use a M10 tap?

HELP!!!!

Chris
 

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Livin' by the sword
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5,180 Posts
Has it sheared off in the housing? Best idea would be a small drill down the middle of the bolt (left handed drill bit is ideal), increasing in size drill until you're as close to the alloy as you dare, and then try a bolt extractor down the hole. A bit of heat on the alloy as well will make it expand more than the steel bolt, and hopefully should twist right out. With alloy being much softer than steel, you don't want to get too close to the alloy with a drill or it'll bugger it.

Left handed drill bits here. Others are available of course, those were the first I found.

Edit: Drill sizes and suitable tap sizes are listed here.
 

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if you have snapped the bolt extractor your in a hole world of pain especially if the extractor is still in their.

otherwise start small then increase the size of the drill till almost at the same size as the bolt.

Then tap out with the correct tap etc

Good luck buddy!!!!
 

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I ate a big red candle !!
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10,384 Posts
Does the hole go all the way through? if it does smash it out then drill and tap the hole for a M12
 

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I ate a big red candle !!
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10,384 Posts
To tap M10 you need something like a 8.5mm drill so if you drill it 10mm you looking at a M12 tap
 
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