Loosening stuck bolts w/o shearing?

[DrWin]

So, I need to remove the valve covers and the coolant Y-pipe in the VOD. Legend has it that I could easily shear one or more of them. Poking around on this site and elsewhere, I get the impression that there are several ways of removing the stuck bolts. Or at least making it easier, all have to do with heating/cooling.
(I suppose we are exploiting the difference in thermal rate of expansion between the steel bolt and the aluminum engine block?)


Heating with propane torch.
Heating by shorting a car battery through the bolt.
Heating with induction, special tool.
Cooling by cold spray from a can. (It's cold! It's damn cold!)


I'm partial to going with the special induction tool or the spray can, since it seems easiest to control.
Could someone advice what your prefered methods are, what works best, and especially if any of the above mentioned have gone wrong/should be avoided?

[Gregadeth]

This works pretty well:
https://images.thdstatic.com/productImages/bdfb61a1-1d6b-4282-be93-563a5581b1c4/svn/blaster-lubricants-16-pb-ds-64_600.jpg
Blaster 16-PB Penetrating Catalyst - 11 oz. https://www.amazon.com/dp/B00XOSYNM6/

[Helirich]

I think the induction tool would be best although I’ve never used one. It might be hard to use in some locations. A actalen torch is probably the quickest, but it also can be hard to use in certain locations. A propane is not so good because you have a lot of heat in the area before you get the bolt/nut red hot. I’ve used the battery deal with great success. It would be nice to build a proper setup. I only used some old jumper cables.

I watched a utube video where they compared penetrant sprays. I can’t remember the best one, but I couldn’t get it locally. (PB and WD were not at the top of the list)

[SupercoolBill]

Been breaking bolts left and right on my project. A buddy just gave me one of these to try. 67883

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[82DMC12]

I don't have any experience with cold sprays or induction. I'm curious about them though and would try them, given the opportunity.

Most of my research seems to indicate that a mixture of 50/50 acetone and auto transmission fluid is a very good penetrating oil. There is also a spray called Aerokroil which is fairly expensive but seems to be known as the best retail spray there is. Hard to find but it's on Amazon. I bought some this year while doing a full front and rear chassis refurbishment and VOD project and so far I've been very happy with it. It was recommended to me by a mobile truck repair technician.

https://www.amazon.com/Kano-Aerokroil-Penetrating-aerosol-AEROKROIL/dp/B000F09CEA/

I've also used MAP with a Bernzomatic TS8000 swirling burner and that works pretty well too. Acetylene is apparently "the best" but not easy for a Sunday shadetree guy to get a hold of in a pinch. Many hundreds of dollars in equipment just to get set up for something you will rarely use.

So, for the regular guy wrenching, my suggestion is an oil can with 50/50 acetone + ATF, a can of Aerokroil, and a good quality MAP torch. But for real, patience is the main thing you need. Recognize which bolts are likely to be a problem and soak them for a couple days first. Spray them twice a day until GO TIME. Strike the bolt head squarely with a hammer every now and then to loosen them up. Hit the surrounding metal (NOT the bolt head) with some heat, and then try to turn them out. Best to use a 6-point socket and turn the bolt hard the first time. If you try to go slow, it's more likely to twist the metal so it breaks. Give it a good firm turn so it shocks loose. If it's still feeling tight, spray more penetrating oil and wait. Then turn it out maybe one full turn, then back in half a turn, and go back and forth between those two points with the ratchet until it's moving freely. Then go another half turn or full turn past that point. Stop, and turn it back into the hole, back and forth until it's loose. And keep coming out like that. Just a bit further each time.

Get the bolt out, blow the hole out with compressed air, and replace the bolt if it's at all rusty or suspect. Oil the new bolt with cutting and tapping oil and run it in a couple times to make sure the threads are good and lubricated. That way you don't make things worse and you'll be less likely the crossthead when re-installing.

If the threads are open on the other side, like for example the holes that you screw the sway bar into the front frame extension, spray both sides of the bolt. And that would be very easy to chase the threads out with a quality thread tap before re-installing. There is a special tap for blind threaded holes but I don't own any of those.

[David T]

The reason the bolts break is that you have plated steel bolts in aluminum and eventually the plating on the bolts corrodes allowing the steel and aluminum to corrode together. Hard to know which bolts will break, some will come out easily and others will just twist right off. Even with precautions you can easily break bolts. My favorite method is an acetylene torch but you can't always use it because of combustibles nearly or heat sensitive materials. Sometimes sprays and liquids can be helpful but it is always hard to get them where they need to be. They seem to work better once you can get the bolt to move even if only a little. The best advice is when you take the bolts out, turn them back-and-forth a little at a time til it comes out. Just realize no matter what you do, you may have to deal with at least 1 broken bolt.

[JohnnyK]

I've never had any luck with the cold sprays on 'really' stuck bolts. Maybe it works fine on stubborn bolts.

Generally you need the bolt red hot. Whether it be from oxy-fuel or induction, that doesn't matter (I have an induction tool, but it's pretty cumbersome). As mentioned, propane takes so long (and won't ever get hot enough as far as I am concerned), you start heating other parts as you wait.

[DrWin]

Been breaking bolts left and right on my project. A buddy just gave me one of these to try. 67883

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Well, did you try it? :)

[DrWin]

I don't have any experience with cold sprays or induction. I'm curious about them though and would try them, given the opportunity.

Most of my research seems to indicate that a mixture of 50/50 acetone and auto transmission fluid is a very good penetrating oil. There is also a spray called Aerokroil which is fairly expensive but seems to be known as the best retail spray there is. Hard to find but it's on Amazon. I bought some this year while doing a full front and rear chassis refurbishment and VOD project and so far I've been very happy with it. It was recommended to me by a mobile truck repair technician.

https://www.amazon.com/Kano-Aerokroil-Penetrating-aerosol-AEROKROIL/dp/B000F09CEA/

I've also used MAP with a Bernzomatic TS8000 swirling burner and that works pretty well too. Acetylene is apparently "the best" but not easy for a Sunday shadetree guy to get a hold of in a pinch. Many hundreds of dollars in equipment just to get set up for something you will rarely use.

So, for the regular guy wrenching, my suggestion is an oil can with 50/50 acetone + ATF, a can of Aerokroil, and a good quality MAP torch. But for real, patience is the main thing you need. Recognize which bolts are likely to be a problem and soak them for a couple days first. Spray them twice a day until GO TIME. Strike the bolt head squarely with a hammer every now and then to loosen them up. Hit the surrounding metal (NOT the bolt head) with some heat, and then try to turn them out. Best to use a 6-point socket and turn the bolt hard the first time. If you try to go slow, it's more likely to twist the metal so it breaks. Give it a good firm turn so it shocks loose. If it's still feeling tight, spray more penetrating oil and wait. Then turn it out maybe one full turn, then back in half a turn, and go back and forth between those two points with the ratchet until it's moving freely. Then go another half turn or full turn past that point. Stop, and turn it back into the hole, back and forth until it's loose. And keep coming out like that. Just a bit further each time.

Get the bolt out, blow the hole out with compressed air, and replace the bolt if it's at all rusty or suspect. Oil the new bolt with cutting and tapping oil and run it in a couple times to make sure the threads are good and lubricated. That way you don't make things worse and you'll be less likely the crossthead when re-installing.

If the threads are open on the other side, like for example the holes that you screw the sway bar into the front frame extension, spray both sides of the bolt. And that would be very easy to chase the threads out with a quality thread tap before re-installing. There is a special tap for blind threaded holes but I don't own any of those.

Well - I do have som acetone standing around and also some ATF Dex II, so why don't I try that? Thanks for the tip. :) I suspect I'll try induction over open flame b/c I'm not really confident that I wont make more trouble that progress with an open flame in my (inexperienced) hands.

[DrWin]

The reason the bolts break is that you have plated steel bolts in aluminum and eventually the plating on the bolts corrodes allowing the steel and aluminum to corrode together. Hard to know which bolts will break, some will come out easily and others will just twist right off. Even with precautions you can easily break bolts. My favorite method is an acetylene torch but you can't always use it because of combustibles nearly or heat sensitive materials. Sometimes sprays and liquids can be helpful but it is always hard to get them where they need to be. They seem to work better once you can get the bolt to move even if only a little. The best advice is when you take the bolts out, turn them back-and-forth a little at a time til it comes out. Just realize no matter what you do, you may have to deal with at least 1 broken bolt.

I suppose you are right. I'll have to cross that bridge once I get there. Hopefully not this winter, but if that happens, I'll know where to ask about removing the sheared bolt(s). :)

[DrWin]

I've never had any luck with the cold sprays on 'really' stuck bolts. Maybe it works fine on stubborn bolts.

Generally you need the bolt red hot. Whether it be from oxy-fuel or induction, that doesn't matter (I have an induction tool, but it's pretty cumbersome). As mentioned, propane takes so long (and won't ever get hot enough as far as I am concerned), you start heating other parts as you wait.

Actually that sort of makes sense. Freezing the bolt changes the temperature perhaps -40*C, while heating it might add several +100*C's, which means the change in volume is gonna be that much bigger. I'll try the acetone/ATF fluid + an induction tool. :)

[David T]

You are going to have a hard time getting heated what you need heated. All you can heat is the head of the bolt and what is really stuck is the threaded end on the other side. To get that hot enough you are going to have to heat the head up to cherry red for a while. Even with that, you aren't going to heat it enough but you will soften the head end so much that if you don't let it cool before trying to loosen it, you will just twist it off. Like I said, try just loosening it a tiny bit, spray your favorite stuff on it and then work it back and forth till it comes out or breaks.

[Helirich]

You are going to have a hard time getting heated what you need heated. All you can heat is the head of the bolt and what is really stuck is the threaded end on the other side. To get that hot enough you are going to have to heat the head up to cherry red for a while. Even with that, you aren't going to heat it enough but you will soften the head end so much that if you don't let it cool before trying to loosen it, you will just twist it off. Like I said, try just loosening it a tiny bit, spray your favorite stuff on it and then work it back and forth till it comes out or breaks.

That’s one thing about the battery trick. You would expect the most heat at the area of most electrical resistance. We are assuming the threads are rusted/corroded. Rust is a poor conductor, so maybe the most heat would be right where it’s needed. Not sure if that would make it likly to strip the threads out, but at least the bolt/stud should come out.

[Bitsyncmaster]

That’s one thing about the battery trick. You would expect the most heat at the area of most electrical resistance. We are assuming the threads are rusted/corroded. Rust is a poor conductor, so maybe the most heat would be right where it’s needed. Not sure if that would make it likly to strip the threads out, but at least the bolt/stud should come out.

I agree. Probably puts the heat right where it's needed. Unless it's so much heat it welds that spot.

[DrWin]

You are going to have a hard time getting heated what you need heated. All you can heat is the head of the bolt and what is really stuck is the threaded end on the other side. To get that hot enough you are going to have to heat the head up to cherry red for a while. Even with that, you aren't going to heat it enough but you will soften the head end so much that if you don't let it cool before trying to loosen it, you will just twist it off. Like I said, try just loosening it a tiny bit, spray your favorite stuff on it and then work it back and forth till it comes out or breaks.

True. Maybe it would make sense to apply the heat first, only to make room for the penetrant to enter between the bolt and the engine block. Then let it cool before proceeding as you suggest. Hmm...

[DrWin]

I agree. Probably puts the heat right where it's needed. Unless it's so much heat it welds that spot.
Yeah - that's the rub. There is an element of unpredictability there, that I don't appreciate.

[DrWin]

Going with the thin (acetone) phase, that looks like it has ATF dissolved in it. The thick (ATF fase) seems not to be diluted.
67887

[DMC-Ron]

Been breaking bolts left and right on my project. A buddy just gave me one of these to try. 67883

Sent from my SM-G970U using Tapatalk

I'm also curious about the induction unit. Seems like a slam dunk if you're working to loosen a nut and have access. But how well will it work on a bolt or stud? Let us know what you find if you try it.

Ron

[John U]

Heat and a battery powered impact gun that doesn't have alot of torque

[Helirich]

I agree. Probably puts the heat right where it's needed. Unless it's so much heat it welds that spot.

I admit I’m a poor welder, but I find it nearly impossible to weld rust or aluminum corrosion. Also, welding steel to aluminum is very difficult. Lol. But we all know Murphy will help at times like that.

[SupercoolBill]

OMG [emoji44]...this thing blew my mind!!
I need to get my own!

I honestly was amazed. I literally don't understand how the wire on this device gets the object so hot so fast. It's like a an oxygen acetylene torch! 678956789667897

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[DMC-81]

Hi,
I used penetrating oil, tapping the head with a hammer, and patience when removing the Y pipe (and any other stuck engine bolts). Be careful as the bolts are only 7 mm. Don't use a socket/ratchet. Just use a combination wrench and your hand - alternating between loosening and tightening once you get them to crack. The goal is to gently coax them loose. It is very easy to snap these bolts.

http://dmctalk.org/attachment.php?attachmentid=36417&d=1441154916

For Exhaust:
Here is the technique I used when restoring my rusted exhaust:

http://dmctalk.org/showthread.php?14704-Refurbishing-stock-exhaust&p=212310&viewfull=1#post212310

If you are working on exhaust manifold studs, be very careful when using heat as the head gasket is nearby. Heat destroys the head gasket. I have seen head gasket jobs suspiciously following exhaust manifold jobs.

[SupercoolBill]

Nobody has mentioned it, maybe because we are talking about loosening but Left Hand Drill Bits.
I am always amazed by how many people have never used LEFT HAND DRILL BITS!!
Even though I hate the name I love using them. They should be called Counter Clockwise drill bits though. Or on the other side of the pond, Anti-clockwise.

I can't even tell you how many snapped off screws and bolts I have seen just screw themselves out as I was drilling them with LH drill bits. In fact I have had such good luck with LH drill bits that I don't even waste a lot of time trying to remove stuck bolts and screws. I just snap them off, remove the part that was attached, then proceed to drill out the fastener. 67920

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[DMC-81]

Nobody has mentioned it, maybe because we are talking about loosening but Left Hand Drill Bits.
I am always amazed by how many people have never used LEFT HAND DRILL BITS!!
Even though I hate the name I love using them. They should be called Counter Clockwise drill bits though. Or on the other side of the pond, Anti-clockwise.

I can't even tell you how many snapped off screws and bolts I have seen just screw themselves out as I was drilling them with LH drill bits. In fact I have had such good luck with LH drill bits that I don't even waste a lot of time trying to remove stuck bolts and screws. I just snap them off, remove the part that was attached, then proceed to drill out the fastener. 67920

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This reads like an infomercial on left hand drill bits. Lol.

Yes, I have used these and screw extractors, but the title of the thread is loosening bolts without shearing. IMO, purposefully snapping off bolts only to have to drill them out is asking for extra effort and risk. You only need to have the drill slip off the hardened bolt and then you drill off-center and begin damaging the soft aluminum engine block. It's best to avoid that where possible.

[SupercoolBill]

This reads like an infomercial on left hand drill bits. Lol.

Yes, I have used these and screw extractors, but the title of the thread is loosening bolts without shearing. IMO, purposefully snapping off bolts only to have to drill them out is asking for extra effort and risk. You only need to have the drill slip off the hardened bolt and then you drill off-center and begin damaging the soft aluminum engine block. It's best to avoid that where possible.Yeah I eluded to the "off topicness" of my reply but like I said, I run across a lot of people that have never used these or even heard of them.

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[DrWin]

I admit I’m a poor welder, but I find it nearly impossible to weld rust or aluminum corrosion. Also, welding steel to aluminum is very difficult. Lol. But we all know Murphy will help at times like that.

At least I'm not gonna go fishing for Murphy on a project like this. :)

[DrWin]

Hi,
I used penetrating oil, tapping the head with a hammer, and patience when removing the Y pipe (and any other stuck engine bolts). Be careful as the bolts are only 7 mm. Don't use a socket/ratchet. Just use a combination wrench and your hand - alternating between loosening and tightening once you get them to crack. The goal is to gently coax them loose. It is very easy to snap these bolts.

http://dmctalk.org/attachment.php?attachmentid=36417&d=1441154916

For Exhaust:
Here is the technique I used when restoring my rusted exhaust:

http://dmctalk.org/showthread.php?14704-Refurbishing-stock-exhaust&p=212310&viewfull=1#post212310

If you are working on exhaust manifold studs, be very careful when using heat as the head gasket is nearby. Heat destroys the head gasket. I have seen head gasket jobs suspiciously following exhaust manifold jobs.

Thanks! :) I'm letting the 4th and last bolt on the Y pipe soak until tomorrow. I got the rest today. That last bolt, I could just barely move it 1/8 rotation, but enough to get som penetrant down there (I hope). I'm gonna hit it with the induction heater (for the 5th time) tomorrow and try again.
I'll take your advice and use the combination wrench instead of the ratchet.

Also, thanks for the link, I'm thinking of changing out my exhaust (its rusted through in several places) with a stage 1 exhaust.

A question, since I noticed that your valve covers are off. Are those bolts hard to loosen as well? I have to get down there to change the gaskets and adjust the valves. I can tell that the recesses in the valve covers are so small that they'll prevent me from using the induction heater. (Hmmm....)

[DrWin]

This reads like an infomercial on left hand drill bits. Lol.

Yes, I have used these and screw extractors, but the title of the thread is loosening bolts without shearing. IMO, purposefully snapping off bolts only to have to drill them out is asking for extra effort and risk. You only need to have the drill slip off the hardened bolt and then you drill off-center and begin damaging the soft aluminum engine block. It's best to avoid that where possible.

Agree with Dana - I'm super extra risk averse when it comes to the DMC-12. BUT - I like the idea, I gotta get me a set of those.

[82DMC12]

Thanks! :) I'm letting the 4th and last bolt on the Y pipe soak until tomorrow. I got the rest today. That last bolt, I could just barely move it 1/8 rotation, but enough to get som penetrant down there (I hope). I'm gonna hit it with the induction heater (for the 5th time) tomorrow and try again.
I'll take your advice and use the combination wrench instead of the ratchet.

Also, thanks for the link, I'm thinking of changing out my exhaust (its rusted through in several places) with a stage 1 exhaust.

A question, since I noticed that your valve covers are off. Are those bolts hard to loosen as well? I have to get down there to change the gaskets and adjust the valves. I can tell that the recesses in the valve covers are so small that they'll prevent me from using the induction heater. (Hmmm....)Valve cover gasket bolts should not be a problem, they are not getting wet with water like the y pipe bolts sometimes are. Also a lot more likely for the y-pipe bolts to get corroded with dirt and garbage around them because you simply can't see them down there and they don't get cleaned off.

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[Helirich]

Nobody has mentioned it, maybe because we are talking about loosening but Left Hand Drill Bits.
I am always amazed by how many people have never used LEFT HAND DRILL BITS!!
Even though I hate the name I love using them. They should be called Counter Clockwise drill bits though. Or on the other side of the pond, Anti-clockwise.

I can't even tell you how many snapped off screws and bolts I have seen just screw themselves out as I was drilling them with LH drill bits. In fact I have had such good luck with LH drill bits that I don't even waste a lot of time trying to remove stuck bolts and screws. I just snap them off, remove the part that was attached, then proceed to drill out the fastener. 67920

Sent from my SM-G970U using Tapatalk

Ha-ha, I don’t know if I would go so far as to snap them off on purpose, but yes, I go right to the left hand bit after braking a bolt. I’ve given up on “easy outs”.

[SupercoolBill]

Ha-ha, I don’t know if I would go so far as to snap them off on purpose, but yes, I go right to the left hand bit after braking a bolt. I’ve given up on “easy outs”.Yeah easy outs are rubbish. I have never had good luck with them. They just widen the stud and make it jam in there all the more. Then when they snap off in there....oh boy....your nackered then!!

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[DrWin]

This mornings events leads us directly to: http://dmctalk.org/showthread.php?19224-Loosening-stuck-bolts :(

[Ethan Rode]

I've done probably 10-11 Y-pipe removals.

In my experience, there's no way to know how bad your bolts are before you remove them. In three or four of the cars I've seen the bolts get locked into the y-pipe. I'll consider it lucky if I only break one or two. I think I've only had two cars where no bolts broke.

Point being... It's ok if the bolts break; have a strategy for when they do, and don't freak out about it.

I have two methods depending on how the bolt is broken that work consistently:

-If there is enough of the bolt shank sticking out of the block to pass fully through an 8mm nut, clean up the shank and weld a nut on. If there isn't enough bolt left to pass through a nut, don't waste your time unless you're able to TIG weld the nut on, and really get good penetration into the remains of the bolt

-If the bolt is broken near flush with the block, file the head flat, center punch the shank and drill the bolt out. Best practices are important here, start small, and step up your hole size in small steps. I believe the bolts were case hardened, so the centers aren't very hard.

With both methods, and regardless of how everything came out, I recommend Heli-Coils or Time-Serts in all the holes before the Y-pipe goes on. It's cheap insurance.

From experience, I'd advise against:
- Easy-Outs, they are blind holes in a very confined space. A broken Easy-out will ruin your day
- Ox-Acetylene Torch, The melting point of the block is lower than the point where the corrosion bond will break on a steel bolt. Mapp Gas is as hot as I'd recommend.

[SupercoolBill]

I've done probably 10-11 Y-pipe removals.

In my experience, there's no way to know how bad your bolts are before you remove them. In three or four of the cars I've seen the bolts get locked into the y-pipe. I'll consider it lucky if I only break one or two. I think I've only had two cars where no bolts broke.

Point being... It's ok if the bolts break; have a strategy for when they do, and don't freak out about it.

I have two methods depending on how the bolt is broken that work consistently:

-If there is enough of the bolt shank sticking out of the block to pass fully through an 8mm nut, clean up the shank and weld a nut on. If there isn't enough bolt left to pass through a nut, don't waste your time unless you're able to TIG weld the nut on, and really get good penetration into the remains of the bolt

-If the bolt is broken near flush with the block, file the head flat, center punch the shank and drill the bolt out. Best practices are important here, start small, and step up your hole size in small steps. I believe the bolts were case hardened, so the centers aren't very hard.

With both methods, and regardless of how everything came out, I recommend Heli-Coils or Time-Serts in all the holes before the Y-pipe goes on. It's cheap insurance.

From experience, I'd advise against:
- Easy-Outs, they are blind holes in a very confined space. A broken Easy-out will ruin your day
- Ox-Acetylene Torch, The melting point of the block is lower than the point where the corrosion bond will break on a steel bolt. Mapp Gas is as hot as I'd recommend.Great advice. I am going to be removing the exhaust manifolds and connectors from my engine soon and mine is one of the worst I have seen as far as rust.
I should print out what you said and tape it to the wall in my shop.

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[SupercoolBill]

Can you expound on this "Regardless of how everything came out, I recommend Heli-Coils or Time-Serts in all the holes before the Y-pipe goes on. It's cheap insurance."
So even if the threads were saved you still drill out the threads and do Heli-coils?
Are you talking about the engine block due to the fact that it is aluminum? I did this on my 1970 BMW motorcycle that I restored. The engine is all aluminum. I got sick of finding stripped out threads so I just started Heli-coiling every threaded hole in the block Eben if the threads were ok.

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[dmcman73]

Can you expound on this "Regardless of how everything came out, I recommend Heli-Coils or Time-Serts in all the holes before the Y-pipe goes on. It's cheap insurance."
So even if the threads were saved you still drill out the threads and do Heli-coils?
Are you talking about the engine block due to the fact that it is aluminum? I did this on my 1970 BMW motorcycle that I restored. The engine is all aluminum. I got sick of finding stripped out threads so I just started Heli-coiling every threaded hole in the block Eben if the threads were ok.

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Don't drill out good threads to install Time-Serts or Helicoils, just drill out stripped ones or ones where you can not torque the bolts down properly.

Also, stay away from HeliCoils, they are the worst of the worst...I still can't understand why people still like them, time-serts are the best there is and are permanent, they are a bit pricey and require special tools to install, but they are well worth it.

[DrWin]

I've done probably 10-11 Y-pipe removals.

In my experience, there's no way to know how bad your bolts are before you remove them. In three or four of the cars I've seen the bolts get locked into the y-pipe. I'll consider it lucky if I only break one or two. I think I've only had two cars where no bolts broke.

Point being... It's ok if the bolts break; have a strategy for when they do, and don't freak out about it.

I have two methods depending on how the bolt is broken that work consistently:

-If there is enough of the bolt shank sticking out of the block to pass fully through an 8mm nut, clean up the shank and weld a nut on. If there isn't enough bolt left to pass through a nut, don't waste your time unless you're able to TIG weld the nut on, and really get good penetration into the remains of the bolt

-If the bolt is broken near flush with the block, file the head flat, center punch the shank and drill the bolt out. Best practices are important here, start small, and step up your hole size in small steps. I believe the bolts were case hardened, so the centers aren't very hard.

With both methods, and regardless of how everything came out, I recommend Heli-Coils or Time-Serts in all the holes before the Y-pipe goes on. It's cheap insurance.

From experience, I'd advise against:
- Easy-Outs, they are blind holes in a very confined space. A broken Easy-out will ruin your day
- Ox-Acetylene Torch, The melting point of the block is lower than the point where the corrosion bond will break on a steel bolt. Mapp Gas is as hot as I'd recommend.

Duly noted. I have to drill then.


Don't drill out good threads to install Time-Serts or Helicoils, just drill out stripped ones or ones where you can not torque the bolts down properly.

Also, stay away from HeliCoils, they are the worst of the worst...I still can't understand why people still like them, time-serts are the best there is and are permanent, they are a bit pricey and require special tools to install, but they are well worth it.

Time-Sets it is then. :)

[SupercoolBill]

Don't drill out good threads to install Time-Serts or Helicoils, just drill out stripped ones or ones where you can not torque the bolts down properly.

Also, stay away from HeliCoils, they are the worst of the worst...I still can't understand why people still like them, time-serts are the best there is and are permanent, they are a bit pricey and require special tools to install, but they are well worth it.I thought that they both required the tool and were permanent. Maybe I have been using timeserts and not Helicoil then

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[Ethan Rode]

Don't drill out good threads to install Time-Serts or Helicoils, just drill out stripped ones or ones where you can not torque the bolts down properly.

Also, stay away from HeliCoils, they are the worst of the worst...I still can't understand why people still like them, time-serts are the best there is and are permanent, they are a bit pricey and require special tools to install, but they are well worth it.

I can't say I've had a problem with Heli-Coils, or coil type inserts, as long as they are installed properly and not over-torqued. Time-serts are a better solution for sure. However they require more material to be removed, and frankly more skill to get right. Also, TimeSert doesn't offer stainless inserts in M7, while Heli-Coils are stainless.

Since I offer a warranty with my work, I replace all the threads under the Y-pipe because the "light alloy" that the block is made of is junk. As long as the torque spec is not exceeded (14 ft/lb, I believe) these bolts will remain serviceable for the next guy in 15 years, and help keep the car on the road.

The cylinder heads are made out of a much more resilient alloy, so there is not usually a need to repair exhaust stud holes, unless there has been pullout.

[Bitsyncmaster]

With installing the inserts you have a much stronger connection. You can use more force if the bolt requires it because the insert is bonding to more area of the soft aluminum. When we were making castings for the military we always had inserts in all bolt holes.

[SupercoolBill]

With installing the inserts you have a much stronger connection. You can use more force if the bolt requires it because the insert is bonding to more area of the soft aluminum. When we were making castings for the military we always had inserts in all bolt holes.Yeah i agree. Which is why I switched the threaded holes in my motorcycle engine (which was aluminum with SS fasteners) to SS Helicoils. I think that every threaded hole in aluminum on an engine should have a SS thread insert locktited in it. Just my opinion

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[dmcman73]

I thought that they both required the tool and were permanent. Maybe I have been using timeserts and not Helicoil then

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The Time-serts comes with a drill bit, a counter sink bit, a tap and a special tool to install the time-sert (it kind of looks like a tap) that flares out the base of it once it's fully seated.

Helicoils just require a drill bit, tap and plastic tool to assists in installing them.

[dmcman73]

....Also, TimeSert doesn't offer stainless inserts in M7, while Heli-Coils are stainless.


Unless you're installing stainless bolts in the stainless helicoils, it really doesn't matter, any steel bolt will seize on the stainless and when you go to remove them later on, you'll also be pulling out the helicoil as well and create a bigger mess. I've had bolts in time-serts for years and I've been able to remove the bolt with no issues at all. Helicoils are just "springs" where I've had them pull put when torquing bolts to spec. Time-serts are steel with real threads in them and are much much tougher.

The Time-serts really do not need that much material removed, the outer portion of the time-sert is usually just the next size up.

[SupercoolBill]

The Time-serts comes with a drill bit, a counter sink bit, a tap and a special tool to install the time-sert (it kind of looks like a tap) that flares out the base of it once it's fully seated.

Helicoils just require a drill bit, tap and plastic tool to assists in installing them.Ok I have helicoils then. It's been over a year since I used my kit. I put locktite on the threads to lock the insert in place

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