Need Tips on Removing Broken Tap

[bulletpruf]

Fellas -

I picked up a 10 bolt 3.90 rear diff for my 68 GTO a few years ago. It was in good shape, but I noticed it had a larger bolt in the bottom middle position on the rear diff cover, so I figured someone had just stripped the threads, drilled it out, and installed a larger bolt.

I was partially correct. They stripped the threads, and then when tapping it for a larger bolt the broke the tap off fairly deep inside. It's 1/2" deep. The bolts holding the cover on are about 1" long, so he had a 1/2" long 3/8" bolt in place of the 1" long 5/16" bolt that should be there.

I'd like to get the tap out, but no luck so far. No luck with drilling it out with HSS drill bits, of course. And I tried to put a dent in it with a chisel; something a screwdriver could grab. Then I could use an impact screwdriver to get it out, but no luck there. The bit is just too damn hard.

I did hit it with some Kroil and some heat (propane torch) but I can't get the tap to turn by jamming needle nose pilers in there and trying to turn it.

Any tips on how to get it out? At this point, I can think of three options - break or shatter the bit, piece by piece; drill it out, but with something significantly harder than HSS; or somehow get it to turn so I could back it out.

Thanks,

Scott

 

[dkroth]

Use a TIG welder to build up a stud on the back of the tap. Grab it with a vise grip and twist it out. The heat cycling will help break it loose.

Weld a nut onto the broken tap and spin it out with a wrench. Again, the heat cycles....







.

 

[shawhite]

Have you tried a tap extractor? There is a tool made just for this

https://www.newmantools.com/walton/extrtap.htm

 

[rlitman]

I've had the best luck by burning them out with an oxy-acetylene torch. Just use a brazing (one hole) tip, and heat the tap ONLY until it's glowing yellow, and then slowly turn off the acetylene and watch it disappear into a shower of sparks.

 

[bulletpruf]

Use a TIG welder to build up a stud on the back of the tap. Grab it with a vise grip and twist it out. The heat cycling will help break it loose.

Weld a nut onto the broken tap and spin it out with a wrench. Again, the heat cycles....


.

I don't have a TIG welder. Wonder if this would be a good enough excuse to drop $1500 on one...

Tap is broken off 1/2" deep. Too deep to weld a nut on there and get a wrench on it, unless it was something tiny.

Have you tried a tap extractor? There is a tool made just for this

https://www.newmantools.com/walton/extrtap.htm

I wasn't familiar with these. I ordered a set. Should be here tomorrow. I'm not super confident that they'll work, however, because it seemed to be really jammed in there. I'll continue to use heat and Kroil to give myself the best possible chance.

I've had the best luck by burning them out with an oxy-acetylene torch. Just use a brazing (one hole) tip, and heat the tap ONLY until it's glowing yellow, and then slowly turn off the acetylene and watch it disappear into a shower of sparks.

I have an o/a torch, but not very handy with it. If the tap extractor doesn't work, I'll give this a try.

What about a titanium drill bit? Something that will drill through the tap?

 

[WhoWhatNow]

Find a machine shop nearby with an EDM.

 

[ez-duzit]

I've milled them out using a carbide end mill, but having someone EDM it out would be easy.

 

[larry_g]

X3 on the EDM.

lg
no neat sig line

 

[Stadger]

I usually keep trying with progressively more expensive drill bits and bigger taps until I have sufficiently filled the hole and then throw the part away. Actually, the last time this happened I used a very small drill bit and drilled the aluminum around what is left of the tap. After drilling about half way around the periphery, the broken tap came loose enough to twist out. Finished it up with a helicoil. No need to find a machine shop that will take such a small job and no need to buy a tig welder and learn how to use it.

 

[Monza Harry]

You will need a carbide tipped drill at the least, solid would be better one way, but worse the other. Carbide is brittle and it will break about 1/2 of the time using it for this type of job, at the break out point they will usually blow up. As such a drill press or mill with a way to control the down feed [a stop]would be Ideal. The tipped drills [cement drill are a cheap way to do this] will melt the "brazed" tip off, if you let it get too hot now you will have a broken solid carbide drill or "fugitive" tip [you know it made a break for freedom] in the hole. if the tap is indeed a 3/8-16NC the tap drill is 5/16" do a 3/16-1/4" cement drill is what I would start with, probably 3/16" as it will measure about 7/32" diameter this will be "way" into the flutes, use a piece of 5/16" transmission line (may need a slight emery rub should spin easily but not sloppy) to keep it centered. This is just what I would do, I am a 35 yr. tool maker and life long "motorhead" so judge your skills with this and enlist help if you aren't sure you will succeed or can live with the consequences. While teaching apprentices I always tell them someone created a way for me to learn by helping/teaching me, giving a good example to emulate, or allowing me to F@#$ things up, to learn for myself. This is your dime so you get to choose. No matter what this will not likely be a quick fix and patients will be king. For coolant compressed air is good a choice while actually drilling, carbide should only be flooded as thermal shock will end with pieces in the hole, you can initially start with a good thick cutting oil in the hole and add only when the drill is cool [finger touch cool] and you will have a good chance of success. I hope this is helpful Harry
edit: Remove drill bit very often and blow out chips! keeping this clean will not likely happen disassemble clean and reassemble for peace of mind.HR

 

[Riggerson]

Carbide end mill works pretty well if you know someone with a mill. A carbide burr also usually works if you can get it in there. You're going to chew up a couple of them. You should be able to buy some NOS or something on ebay.

You might be able to get it out with a carbide drill bit if you're super careful. Pretty good chance you'll also ruin a couple of those bits getting it out.

 

[Wrench97]

I've had the best luck by burning them out with an oxy-acetylene torch. Just use a brazing (one hole) tip, and heat the tap ONLY until it's glowing yellow, and then slowly turn off the acetylene and watch it disappear into a shower of sparks.

+++ Best way I've found without spending more money then the housing is worth.

 

[Kenstone1]

Kind of late to the game, but here's some more tap remover options:
https://www.amazon.com/s?k=broken+t...399777&tag=googhydr-20&ref=pd_sl_64nu0ugkq6_b

 

[rlitman]

+++ Best way I've found without spending more money then the housing is worth.

I will say this, the first time I did it, I was afraid I'd ruin the part. But the secret is that the tap doesn't transfer heat well to the part. The tap is small and heats up in seconds, while the part is a huge heatsink. So, the tap will be glowing bright yellow and approaching melting well before the rest of the part is even reaching a dull red. Because of this, the tap is at a temperature that can be cut with oxygen, while the threads around it are way too cool to be damaged.

And the funny thing is that it works even better taps in aluminum, because aluminum is a better heat sink. That's part of why welding aluminum takes more amps, even though it has a way lower melting point than steel.

Because the job is "cutting" without fuel gas, I've had the best luck by overheating the tap past where I'd normally heat steel to cut with a torch. I'll bring it to forge welding temperatures. Basically, bright yellow with the surface starting to look like melting butter. But there's no harm and continuing to the point that it starts to spark.

And do NOT use a cutting torch. You don't want multiple pre-heat flames.

 

[FANTM58]

Have you tried a tap extractor? There is a tool made just for this

https://www.newmantools.com/walton/extrtap.htm

WOW, thanks I never knew of this tool

 

[pl_silverado]

Carbide burr in a die grinder will make short work of it, just wear gloves, tiny slivers of metal end up everywhere.

 

[bulletpruf]

Find a machine shop nearby with an EDM.

That sounds interesting, but I think I can get this done in the garage with persistence and patience.

I've milled them out using a carbide end mill, but having someone EDM it out would be easy.

Thanks

X3 on the EDM.

lg
no neat sig line

Appreciate the input.

I usually keep trying with progressively more expensive drill bits and bigger taps until I have sufficiently filled the hole and then throw the part away. Actually, the last time this happened I used a very small drill bit and drilled the aluminum around what is left of the tap. After drilling about half way around the periphery, the broken tap came loose enough to twist out. Finished it up with a helicoil. No need to find a machine shop that will take such a small job and no need to buy a tig welder and learn how to use it.

I'm trying not to booger up the metal where I need to cut some threads. But I agree that this doesn't need to go to a machine shop.

You will need a carbide tipped drill at the least, solid would be better one way, but worse the other. Carbide is brittle and it will break about 1/2 of the time using it for this type of job, at the break out point they will usually blow up. As such a drill press or mill with a way to control the down feed [a stop]would be Ideal. The tipped drills [cement drill are a cheap way to do this] will melt the "brazed" tip off, if you let it get too hot now you will have a broken solid carbide drill or "fugitive" tip [you know it made a break for freedom] in the hole. if the tap is indeed a 3/8-16NC the tap drill is 5/16" do a 3/16-1/4" cement drill is what I would start with, probably 3/16" as it will measure about 7/32" diameter this will be "way" into the flutes, use a piece of 5/16" transmission line (may need a slight emery rub should spin easily but not sloppy) to keep it centered. This is just what I would do, I am a 35 yr. tool maker and life long "motorhead" so judge your skills with this and enlist help if you aren't sure you will succeed or can live with the consequences. While teaching apprentices I always tell them someone created a way for me to learn by helping/teaching me, giving a good example to emulate, or allowing me to F@#$ things up, to learn for myself. This is your dime so you get to choose. No matter what this will not likely be a quick fix and patients will be king. For coolant compressed air is good a choice while actually drilling, carbide should only be flooded as thermal shock will end with pieces in the hole, you can initially start with a good thick cutting oil in the hole and add only when the drill is cool [finger touch cool] and you will have a good chance of success. I hope this is helpful Harry
edit: Remove drill bit very often and blow out chips! keeping this clean will not likely happen disassemble clean and reassemble for peace of mind.HR

Hey, excellent tip on using trans line for a guide. That's a great idea.

Thanks

Carbide end mill works pretty well if you know someone with a mill. A carbide burr also usually works if you can get it in there. You're going to chew up a couple of them. You should be able to buy some NOS or something on ebay.

You might be able to get it out with a carbide drill bit if you're super careful. Pretty good chance you'll also ruin a couple of those bits getting it out.

Winner winner, chicken dinner - I have some unused carbide burrs somewhere in the garage; been looking for an excuse to use them.

+++ Best way I've found without spending more money then the housing is worth.

Thanks

Kind of late to the game, but here's some more tap remover options:
https://www.amazon.com/s?k=broken+t...399777&tag=googhydr-20&ref=pd_sl_64nu0ugkq6_b

Thanks for the input. I ordered a set of the tap removers.

I will say this, the first time I did it, I was afraid I'd ruin the part. But the secret is that the tap doesn't transfer heat well to the part. The tap is small and heats up in seconds, while the part is a huge heatsink. So, the tap will be glowing bright yellow and approaching melting well before the rest of the part is even reaching a dull red. Because of this, the tap is at a temperature that can be cut with oxygen, while the threads around it are way too cool to be damaged.

And the funny thing is that it works even better taps in aluminum, because aluminum is a better heat sink. That's part of why welding aluminum takes more amps, even though it has a way lower melting point than steel.

Because the job is "cutting" without fuel gas, I've had the best luck by overheating the tap past where I'd normally heat steel to cut with a torch. I'll bring it to forge welding temperatures. Basically, bright yellow with the surface starting to look like melting butter. But there's no harm and continuing to the point that it starts to spark.

And do NOT use a cutting torch. You don't want multiple pre-heat flames.

Thanks for the input, but this may be a bit much for my rudimentary skills with the oxy acetylene setup.

WOW, thanks I never knew of this tool

Carbide burr in a die grinder will make short work of it, just wear gloves, tiny slivers of metal end up everywhere.

I'm going to try this. Thanks

 

[CJM8515]

Some time back I had an ATV that the case saver broke off the standoffs on the case. Instead of buying an entire case, taking down the entire engine (might as well rebuild it too) I decided to pay someone to weld me up a stand off. All I asked was them to make a blob.



I then took a dremel with this carbide bit and used it to carve out what I wanted https://www.dremel.com/en_US/products/-/show-product/tools/9901-tungsten-carbide-cutter worked like a charm. I used the same bit to carve away enough material to remove broke drill bits, taps, etc as well.Go slow and use cutting fluid and it will work.

 

[3 Gun Shooter]

EDM is the cleanest, easiest way to get a tap out. If you can not find one, I have cut the center out with a diamond tip on a die grinder. It is very slow but once the center is out you can break the teeth away from the sides.

 

[bulletpruf]

Some time back I had an ATV that the case saver broke off the standoffs on the case. Instead of buying an entire case, taking down the entire engine (might as well rebuild it too) I decided to pay someone to weld me up a stand off. All I asked was them to make a blob.

I then took a dremel with this carbide bit and used it to carve out what I wanted https://www.dremel.com/en_US/products/-/show-product/tools/9901-tungsten-carbide-cutter worked like a charm. I used the same bit to carve away enough material to remove broke drill bits, taps, etc as well.Go slow and use cutting fluid and it will work.

Can't get this to load right now, but I'll check it out. Dremel can be pretty handy.

EDM is the cleanest, easiest way to get a tap out. If you can not find one, I have cut the center out with a diamond tip on a die grinder. It is very slow but once the center is out you can break the teeth away from the sides.

That's about where I am with the carbide burr -- about to finish cutting the center out.

Thanks

 

[MoonRise]

Plain plumber's type air-propane torch is not a concentrated enough or hot enough flame to really do this type of job IMHO.

Oxy-fuel flame is the way to go for intense and concentrated flame/heat.

Like rlitman said, a single-flame welding/brazing oxy-acetylene tip in your torch handle and NOT a cutting torch with multiple flame preheat holes (good for heating and then cutting sheet or plate, not so good for heating JUST the recessed broken-off tap in a hole), heat it PDH (pretty dang hot), then slowly turn off the fuel and let the jet of pure O2 do the cutting like usual.

HSS drill bits won't touch the metal on a tap, as you quickly found out.

Left-hand cobalt drill bit -might- have a chance.

Or a small carbide/diamond burr in a Dremel or an Astro Pneumatic pencil die grinder to try and nibble away at the tap.

Like this:

https://www.tools-plus.com/astro-pneumatic-218.html

Or just wait until you get the tap extractor(s) that you ordered and use them.

http://www.waltontools.com/products/remvtap.htm

There are also 'special' SMAW electrodes you can use to weld to the broken tap and build up enough metal so that you can eventually grab it. The relatively heavy flux coating quickly flow out as it melts in order to protect the tapped female threads from insta-welding while still letting the arc and molten electrode flow and bond to the tap (or stud, or whatever).

https://www.lawsonproducts.com/pdfs/PIRFS_Bolt_Stud_Removal_PI.pdf

Or, a shop with an EDM to remove the broken tap.

Good luck, have patience, and let us know when you finally succeed.

 

[Bigblue&Goldie]

You can get carbide drill bits, but they are super sensitive to breaking if not run in a mill or beefy drill press. I drilled out one of those Lang thread repair tools last night (1/4"-20) with a cobalt coated bit with ease. Granted, I did it with my Bridgeport. It probably wasn't AS hard as a tap but it was very brittle, so it was definitely hard.

 

[Rory Bellows]

I would keep beating on it with a chisel. It works I've used this method with success every time. You can also heat it cherry red with your torch and quench with water through several cycles and then beat some more with a chisel. Persistence pays off. You will want to quit and take the easy way out then bam it comes out.

 

[toplessHO]

BP I would hope that the rear is a nodular iron one,and if so isnt that easy to find.
If so I can understand the reasoning for repairing.
I agree that the oxy- acetylene with a very small tip is the way to burn it out
If you have a mig welder,make a sleeve out of copper tubing that fits inside the tapped hole,run the mig wire thru the tubing(weld wont stick to copper) and crank the heat up
using the mig electrode to burn the tap out.
I have an NOS 4 pinion posi unit and a M21 Muncie coded for a 68 RA GTO if interested.

 

[toplessHO]

I would keep beating on it with a chisel. It works I've used this method with success every time. You can also heat it cherry red with your torch and quench with water through several cycles and then beat some more with a chisel. Persistence pays off. You will want to quit and take the easy way out then bam it comes out.

I wouldnt risk cracking the rear...too hard to find.

 

[bulletpruf]

Plain plumber's type air-propane torch is not a concentrated enough or hot enough flame to really do this type of job IMHO.

Oxy-fuel flame is the way to go for intense and concentrated flame/heat.

Like rlitman said, a single-flame welding/brazing oxy-acetylene tip in your torch handle and NOT a cutting torch with multiple flame preheat holes (good for heating and then cutting sheet or plate, not so good for heating JUST the recessed broken-off tap in a hole), heat it PDH (pretty dang hot), then slowly turn off the fuel and let the jet of pure O2 do the cutting like usual.

HSS drill bits won't touch the metal on a tap, as you quickly found out.

Left-hand cobalt drill bit -might- have a chance.

Or a small carbide/diamond burr in a Dremel or an Astro Pneumatic pencil die grinder to try and nibble away at the tap.

Like this:

https://www.tools-plus.com/astro-pneumatic-218.html

Or just wait until you get the tap extractor(s) that you ordered and use them.

http://www.waltontools.com/products/remvtap.htm

There are also 'special' SMAW electrodes you can use to weld to the broken tap and build up enough metal so that you can eventually grab it. The relatively heavy flux coating quickly flow out as it melts in order to protect the tapped female threads from insta-welding while still letting the arc and molten electrode flow and bond to the tap (or stud, or whatever).

https://www.lawsonproducts.com/pdfs/PIRFS_Bolt_Stud_Removal_PI.pdf

Or, a shop with an EDM to remove the broken tap.

Good luck, have patience, and let us know when you finally succeed.

MR -

With the heat, I was just trying to expand things a bit to see if I could loosen them up a bit. I'm just not comfortable enough with my oxyacetylene rig to fire that up on a job like this.

Left handed bits have never worked for me; break every stinking time.

I tried some titanium bits and made very little progress.

Don't need a pencil die grinder for this job (not deep enough to need it) but I'm going to order one just to have. Good piece of gear.

The tap extractors arrived (not cheap - the kit cost $110), but there's not much of the tap left, and I'm going to continue with the die grinder. I also got a set of 1/4" carbide burrs (shank and burr are both 1/4") that should to the trick.

Thanks for the input.

You can get carbide drill bits, but they are super sensitive to breaking if not run in a mill or beefy drill press. I drilled out one of those Lang thread repair tools last night (1/4"-20) with a cobalt coated bit with ease. Granted, I did it with my Bridgeport. It probably wasn't AS hard as a tap but it was very brittle, so it was definitely hard.

Yeah, I don't want to make it any worse with broken off drill bits. Thanks

I would keep beating on it with a chisel. It works I've used this method with success every time. You can also heat it cherry red with your torch and quench with water through several cycles and then beat some more with a chisel. Persistence pays off. You will want to quit and take the easy way out then bam it comes out.

I'm pretty close at this point. Now that I have the right carbide burrs I think I will be able to grind it until it just about falls apart. Thanks

BP I would hope that the rear is a nodular iron one,and if so isnt that easy to find.
If so I can understand the reasoning for repairing.
I agree that the oxy- acetylene with a very small tip is the way to burn it out
If you have a mig welder,make a sleeve out of copper tubing that fits inside the tapped hole,run the mig wire thru the tubing(weld wont stick to copper) and crank the heat up
using the mig electrode to burn the tap out.
I have an NOS 4 pinion posi unit and a M21 Muncie coded for a 68 RA GTO if interested.

Sent you a pm on the 68 GTO bits...

Yes, the rear is the good nodular case, 4 pinion posi, forged axles. Definitely worth saving.

Burning it out with a MIG sounds interesting, but at this point, I'm pretty close to getting it done the the carbide burrs.

Thanks

I wouldnt risk cracking the rear...too hard to find.

Yep. Don't see many of these for sale.

 

[jjeffries]

30 years ago I was doing brakes (on a 74 Alfa GTV!) and broke off a brake bleeder in one of the ATE iron calipers. Young, dumb and lacking a sensitive touch with a wrench, and only developing common sense. Instead of drilling out the remains (easy!) I went to True Value and bought an extractor, which I (of course) promptly snapped, flush with the top of the casting. I took it to a wise old machinist, who pondered the caliper and spoke words I'll never forget:
"Son, you've created the ultimate Rubic's cube here."
I bought a used caliper, swore-off extractors forever and gained some wisdom!
Thanks for providing me with an opportunity to share that favorite anecdote. Best of luck with this and BTW, your GTV Jr. is gorgeous. John/CT

 

[MoonRise]

MR -

With the heat, I was just trying to expand things a bit to see if I could loosen them up a bit. I'm just not comfortable enough with my oxyacetylene rig to fire that up on a job like this.

No problem with knowing your limits.

Just that the flame from a plumbers-type air-propane torch (even a 'good' one) is MUCH different from an oxy-acetylene flame. Temperature and overall 'heat' and how 'concentrated' (or not) the flame is.

Even if you didn't want to attempt to use the oxygen jet to actually burn out the broken tap, using a welding-type single concentrated oxy-acetylene flame at ~5500-6000F to heat the tap is different than a spread-out swirl of heat from a ~3500F air-propane flame.

Left handed bits have never worked for me; break every stinking time.

I tried some titanium bits and made very little progress.

"titanium bits"? As in the gold-colored titanium nitride (or cheap gold paint as -some- chinesium bits are coated with) that is the coating on the steel drill bit?

The TiN (titanum nitride) coating does NOT magically make a steel drill bit able to drill through something really-really hard (like a broken tap ).

To be able to drill into a really-really hard thing, you need an even harder drill bit. Like cobalt (technically, it's a high cobalt steel alloy, but it's almost always just called a 'cobalt' drill bit).

Or 'carbide'. Like in your die grinder burrs, which are solid tungsten carbide. But often just called 'carbide'.

Don't need a pencil die grinder for this job (not deep enough to need it) but I'm going to order one just to have. Good piece of gear.

The tap extractors arrived (not cheap - the kit cost $110), but there's not much of the tap left, and I'm going to continue with the die grinder. I also got a set of 1/4" carbide burrs (shank and burr are both 1/4") that should to the trick.

Thanks for the input.


Yeah, I don't want to make it any worse with broken off drill bits. Thanks


I'm pretty close at this point. Now that I have the right carbide burrs I think I will be able to grind it until it just about falls apart. Thanks

Keep at it, and let us know when you Git-R-Dun.

 

[bulletpruf]

30 years ago I was doing brakes (on a 74 Alfa GTV!) and broke off a brake bleeder in one of the ATE iron calipers. Young, dumb and lacking a sensitive touch with a wrench, and only developing common sense. Instead of drilling out the remains (easy!) I went to True Value and bought an extractor, which I (of course) promptly snapped, flush with the top of the casting. I took it to a wise old machinist, who pondered the caliper and spoke words I'll never forget:
"Son, you've created the ultimate Rubic's cube here."
I bought a used caliper, swore-off extractors forever and gained some wisdom!
Thanks for providing me with an opportunity to share that favorite anecdote. Best of luck with this and BTW, your GTV Jr. is gorgeous. John/CT

Good story! I have a similar one -- when I was 18 or so, I broke off a bolt in an LS7 454 that I was bolting a TH400 to (was going in my 69 Z/28 clone). Instead of drilling it out, I....wait for it...went to Ace Hardware and bought an EZ Out screw/bolt extractor. Broke that sucker off. But it gets better - I doubled down and broke off ANOTHER EZ Out in the same bolt!

No problem with knowing your limits.

Just that the flame from a plumbers-type air-propane torch (even a 'good' one) is MUCH different from an oxy-acetylene flame. Temperature and overall 'heat' and how 'concentrated' (or not) the flame is.

Even if you didn't want to attempt to use the oxygen jet to actually burn out the broken tap, using a welding-type single concentrated oxy-acetylene flame at ~5500-6000F to heat the tap is different than a spread-out swirl of heat from a ~3500F air-propane flame.

"titanium bits"? As in the gold-colored titanium nitride (or cheap gold paint as -some- chinesium bits are coated with) that is the coating on the steel drill bit?

The TiN (titanum nitride) coating does NOT magically make a steel drill bit able to drill through something really-really hard (like a broken tap ).

To be able to drill into a really-really hard thing, you need an even harder drill bit. Like cobalt (technically, it's a high cobalt steel alloy, but it's almost always just called a 'cobalt' drill bit).

Or 'carbide'. Like in your die grinder burrs, which are solid tungsten carbide. But often just called 'carbide'.



Keep at it, and let us know when you Git-R-Dun.

Thanks for the input on oxy-acetylene. Just need to spend some time with that and my MIG.

On the drill bits, I think I got the cheap stuff. They're brand name, clearly labeled as titanium; didn't say they were just titanium coated. But they weren't very expensive, so they must not be the real thing.

I'll let y'all know when I get 'er dun. I'm taking the day off from work; plan to tackle this and then yank the TH400 for rebuild #2...

Thanks

 

[ez-duzit]

...On the drill bits, I think I got the cheap stuff. They're brand name...

So what's the brand?

 

[Abeo]

I broke off an easy out while trying to repair a tie down bolt in my old truck... I ended up using cheap diamond Dremel bits and took my time carving out the remains of the easy out and snapped bolt. Took a long while, but did the job and saved the threads.

 

[bulletpruf]

So what's the brand?

Dewalt, I think.

I broke off an easy out while trying to repair a tie down bolt in my old truck... I ended up using cheap diamond Dremel bits and took my time carving out the remains of the easy out and snapped bolt. Took a long while, but did the job and saved the threads.

Yeah, that does sound tedious, but if you saved the threads, it was worth it.

Dremel diamond bits are super cheap on Amazon; I just ordered a set of 30 for less than $10.

 

[Shadowdog500]

Do you have a friend with a mill? Removing that tap would be easy with a carbide bit on a mill. If that rear is rare and worth money I wouldn’t monkey around and possibly damage the rear trying to get it out.

 

[ez-duzit]

Dewalt, I think.
...

That would likely be Chinesium.

 

[Lassen Forge]

I know it's been said already, but why chance messing this up any worse? Find someone with an EDM and have it done right.

 

[bulletpruf]

Do you have a friend with a mill? Removing that tap would be easy with a carbide bit on a mill. If that rear is rare and worth money I wouldn’t monkey around and possibly damage the rear trying to get it out.

No, I don't have a friend with a mill.

But even if I did, then I would have to remove the rear diff from the car, bring it to said friend, get this milled out, and then come back home and reinstall the rear diff.

Worse case scenario right now is that I'll end up using a helicoil, but I was going to have to do that already since someone had already drilled out the threads.

Thanks

 

[bulletpruf]

I know it's been said already, but why chance messing this up any worse? Find someone with an EDM and have it done right.

I'm not too worried about "messing this up any worse" -- remember, all this bolt has to do is to hold the rear differential cover on, and any repair (i.e., helicoil) is going to be hidden behind the cover. I really don't think it's necessary to yank out the rear end so I can bring it to a shop with an EDM.

 

[Shadowdog500]

No, I don't have a friend with a mill.

But even if I did, then I would have to remove the rear diff from the car, bring it to said friend, get this milled out, and then come back home and reinstall the rear diff.

Worse case scenario right now is that I'll end up using a helicoil, but I was going to have to do that already since someone had already drilled out the threads.

Thanks

Didn’t realize it was in the car already.

get a cheap $18 dental hand piece and a $10 pack of 10 carbide burrs for it. I have this setup and have used it to remove broken bolts In some oddball places. All it takes is some patience.
Here is a video I made of my setup.

 

[bulletpruf]

Didn’t realize it was in the car already.

get a cheap $18 dental hand piece and a $10 pack of 10 carbide burrs for it. I have this setup and have used it to remove broken bolts In some oddball places. All it takes is some patience.
Here is a video I made of my setup.

That is a pretty handy setup! Definitely need to get one. But it wouldn't work for me because the tap is a few inches inside the housing now. A carbide burr on a small angle grinder is the hot ticket for me.

Thanks

 

[bimmer1980]

I'd definitely be using the torch..... It is surprising on how the torch will heat just the tap or a broken bolt and to a lesser degree, the metal around it.... The small bits will get cherry hot.

It's less about using skill and more of just a steady hand.

If you are concerned about the process.... Try a practice piece. A long coupling nut, clamp it in the vise, thread a bolt in thru the bottom. Then try burning out the bolt from the other side. Worse case, you are out the $5 for a coupling nut and a random bolt.....