How to remove a broken pin from an engine block. Device for drilling broken studs

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In the process of repairing and servicing a car, as well as any other equipment, there is often an urgent need to remove individual elements or the chassis, body panels, etc. In this case, the removal components engine and suspension is often the most problematic operation. The reason is that the units can be tightened with bolts or studs, and the tightening torque is quite large.

If we add to this the temperature changes in engine compartment, oiling, accumulation of dust, dirt and other deposits, it becomes clear that unscrewing various bolts and other fasteners is not only a responsible and time-consuming, but also often a difficult task. In this article we will talk about what you can do if a stud or bolt breaks, as well as how to unscrew a broken bolt.

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The bolt thread is broken, the pin is broken, or the bolt in the engine block is broken: how to unscrew it

So, bolts and studs often “sour”, become covered with rust, and can be overtightened or twisted skewed (not along the threads) during previous operations. This is true for all car models and brands without exception.

In any case, a common situation is when, while unscrewing a bolt, the master stripped the thread, broke the pin, broke off the bolt head, etc. It is also possible that the tightening torque during tightening is greatly exceeded, and the bolt bursts while remaining unscrewed. Naturally, the remaining bolts must be unscrewed, after which the stud or bolt should be replaced.

As a rule, bolts break in cases where the bolt is rusty or stuck, and too much force is applied when unscrewing. This usually affects used cars or cars that are used in difficult conditions. Often, threaded connections begin to create problems as a result of contact with moisture. For the chassis of the car, such contact is inevitable. In the case of an engine, the cylinder head is screwed to the cylinder block, the tightening torque is large.

One way or another, the most problematic situation is that the bolt can be broken flush, that is, unscrew it in the usual way or using simple tools does not seem possible. In other words, the “body” of the bolt does not protrude above the surface. In this case, there are several ways to solve the problem, with the most common being:

drilling a bolt;
unscrewing the bolt by welding;

First of all, the choice of one method or another depends on certain conditions. If the bolt was twisted before breaking, then the main task is to “attach” to its body in order to then unscrew the remaining parts. If it is impossible to turn the bolt, then you need to carefully drill out the remaining body in the hole. Let's look at the available methods in more detail.

Let's start with the fact that for a successful result you need to know how to unscrew a broken bolt, as well as perform a series of additional work before unscrewing.

On initial stage it is necessary to remove dirt, oil residues, rust, etc. from the problem area. It should also be applied to the threaded connection. special remedy so that the bolts become loose. Special cleaners can use this liquid. These are compounds that remove and soften rust, dirt, etc. WD-40 or pure oil is also quite suitable for these purposes.
Let's move on. If the fragment protrudes above the threaded hole, you can also hit it several times with a hammer, the bolt is additionally heated (for example, using a blowtorch). The only thing is that you can hit the bolt or heat it only if other parts, elements or the threaded hole itself are not guaranteed to suffer from such an impact.

If the thread has been broken off (the bolt is spinning), then the broken bolt is unscrewed using pliers, an adjustable wrench, etc. You can also use a chisel, a hacksaw or a grinder to make a “groove” on the body of the bolt, after which you can try to unscrew the piece with a regular screwdriver.

Also, in the fragment, if the body protrudes high enough, a through transverse hole is drilled into which a metal rod, nail, screwdriver, etc. is inserted. Then the resulting lever allows you to unscrew the fragment using available tools.

Often the body of the bolt does not protrude much above the surface, that is, the bolt is broken almost flush. This makes it difficult to remove residue from the threaded hole. In this case, welding helps a lot. To implement the task, you need to select a bolt with a head similar in diameter, after which you need to weld it using welding machine to the body of the fragment in the threaded hole.

Next, you can try to unscrew the fragment using the key. It is important to remember that welding may be fragile at the joint, so you should not use too much force. Let us add that in addition to welding, sometimes special types of glue are used for such cases. However, this method is not widely used, since these types of glue are not always available at hand, and some doubts are raised about the reliability of fixation using such means.

The most difficult case is considered to be a broken bolt that breaks off, for example, flush with the surface or even lower. Often this situation can be encountered when a bolt breaks off. In this case, the methods described above do not always work. To solve the problem, you need to know how to unscrew debris from a hole, drill a bolt from a car engine block, etc.

First of all, you need to prepare a drill and a set of thin drills. Please note that it is not recommended to perform such work without certain skills. The main task is the need to drill several small holes in the body of the bolt. This is done in such a way that it then becomes possible to connect these small holes into one large one. Next, a screwdriver is inserted into the hole, after which the fragments are unscrewed.

More in a complicated way is cutting a left-hand thread in the body of a broken bolt. In this case, you need a drill and a tap. First, a hole is drilled in the body of the fragment, then the left-hand thread is cut with a tap. Then another bolt is screwed into this thread. After such a bolt is screwed in completely, the fragment should begin to unscrew from the hole.

The last available method for removing a piece of bolt that has broken in a threaded hole is drilling. The method is quite complicated and requires special skills. The main goal is not to damage the thread of the hole itself when drilling out the fragment.

To drill out a fragment, first make a hole in its center with a thin drill. Then the drill is changed to a thicker one, etc. After the walls of the body of the broken bolt become as thin as possible, you should try to break them using metal wire or tweezers. The debris is then removed from the hole. This method If implemented correctly, it eliminates the need to cut a new thread in a hole or restore an existing one.

Let's sum it up

As you can see, there are several ways to unscrew a broken bolt or stud. In each case, it is necessary to separately take into account in advance the nature of the body fragment, the location of the fragment itself, the possibility of access to the problem area, possible consequences heating bolt residues, etc.

Finally, we note that before unscrewing the bolts, it is advisable to carry out treatment to remove dirt and soften rust before starting the procedure. Moreover, if various standard methods of unscrewing do not give the desired result (the bolt does not fit), then it is optimal not to make much effort so as not to break the stud.

The same can be said about tightening studs or bolts. The fact is that fasteners must be tightened with a strictly defined force and in the specified order (for example, covering the cylinder head). Ignoring of this rule often leads to studs or bolts breaking, stretching, deforming, etc.

If such problems arise, it is better to contact experienced specialists who, in many cases, will unscrew the problematic broken or soured bolt. If it is not possible to avoid breaking the bolt, then qualified craftsmen will remove the residue from the hole with minimal risk, and, if necessary, restore the damaged thread.

Why does a bolt break?

The bolt breaks because it is either rusty or stuck. The older the car, the more “bad” bolts there are and the more difficult it will be to repair the car. Most often, older cars have rusty bolts due to frequent contact with moisture.

Long-term use of the machine wears out all the parts and bolts. For example, the chassis of a car is constantly in contact with moisture. So don’t be surprised that something is rusty somewhere.

The best ways to remove bolts

In order to proceed to the actual unscrewing of the bolts, you must first perform preparatory work, or rather, cleaning the work area from all dirt and dust. And the irreplaceable “Vedashka” (WD-40) will help us with this, or you can use machine oil.

If there is none of this, just hit the bolt with a hammer or heat it. But be careful not to damage other elements.

What to do if the bolt breaks above the threaded surface?

Let's consider several options for solving the problem:

You can try to unscrew the bolt using pliers if you managed to “break” the bolt thread a little;

The next method involves using a hacksaw, grinder or chisel. The principle of operation is as follows: make a transverse hole for a screwdriver, then use the screwdriver itself to unscrew the bolt.

The third option will involve using a welding machine. Follow the following instructions: take a bolt of a similar size and weld it to the broken one. Use a wrench to unscrew the bolt, but be careful not to overdo it. You can use glue instead of welding, but there is a chance that the job won't get done, so use welding to be safe.

The bolt broke off flush with or below the surface.

If you don't know exactly how your bolt broke, look on the Internet for photos of broken bolts and determine which one is similar to yours. Let's look at solutions for how to properly unscrew a broken bolt:

Take a drill with a thin drill, drill two or three or more thin holes in the body of the bolt. This is done in order to combine them later. Insert a screwdriver into the hole and unscrew the piece of bolt.

The second method involves more drastic measures. You will need: a drill, a tap, work experience and a lot of patience. Do the following: drill a hole in the center of the bolt itself. Then you need to carefully cut a left-hand thread in it.

The moment you screw a new bolt with a left-hand thread into the made thread, then as soon as you reach the end, the old bolt should begin to unscrew.

The bolt broke flush with the surface

Be careful, there is a chance of damaging the threads. Instructions for unscrewing bolts without damaging the threads:

Drill a hole in the center (use a thin drill);
Replace the thin drill with a thick one and drill some more;
When the base of the bolt is almost gone and the walls become very thin, try to break the remaining threads. Use thin sharpened wire or tweezers for this.
If you did everything correctly, then you will not have to cut a new thread or “drive” the old one.
If you have a left-hand threaded "extractor" you will be able to use it. Unscrew the remaining fragments.

If you can’t unscrew the broken bolt in any way, and even no method helped, leave this problem. It is better to trust a person who has already encountered such problems and knows from experience how and what to do.

Note!

Do not under any circumstances complicate your work or act rashly, this will lead to other problems. We hope you found this article helpful.

Note!

How to unscrew the pin? Let's consider several methods, taking into account the condition of the stud and the available tool.

How to unscrew a stud by its threaded part

If the stud is long enough and a threaded part for 2 or more nuts is available, then we use one of the following methods:

screw on the nut, screw the second one all the way into the first one (it is advisable to use tall nuts), then unscrew the stud with a mechanic’s tool (wrench or other);
use a special tool - a hairpin driver, suitable for the size of a hairpin or a universal one.

An eccentric pin driver is convenient and effective - the greater the force applied to it, the stronger it clamps the pin with the eccentric notch.

How to unscrew a stud if there is only thread available for 1 nut? In this case, at least 4 methods are available:

cut the nut on one side with a hacksaw (the direction of the cut is along the axis of the threaded part), screw it onto the stud, clamp it with a pipe wrench so tightly that the threaded part, choosing a gap in the cut, tightly grips the stud, direct the force in the direction of unscrewing;
screw the nut onto the thread, weld it to the stud (for example, with a semi-automatic welding machine) and unscrew it with a wrench (or a head with a knob);
screw the nut onto the thread, drill a recess in the end of the stud (approximately half the diameter of the stud), drive a TORX socket (E-profile, or another similar one with longitudinal ribs) into this recess and unscrew it by the shank of the socket (you can use your second hand to help with this) with an open-end or socket wrench applying force to the nut in addition to the main force on the torx);

In the method with a screwdriver for this purpose would be better suited large version or power version with T-handle.

How to unscrew a hairpin by its smooth cylindrical part

If only the smooth part of the stud is accessible (for example, the threaded part is broken), then the following techniques are applicable;

clamp the cylindrical part in a suitable tool (pliers, a pipe wrench, a small vice, a clamp, or the like) and apply force in the direction of unscrewing;
weld a metal rod to the broken end by welding as a T-shaped handle;
put on a nut of a slightly larger diameter, weld it to the stud in a circle and unscrew it with a wrench;
use a square washer the thickness of a nut or larger, with internal diameter to the same size as the diameter of the cylindrical part of the stud (ideally, if the washer fits tightly on the cylindrical part of the stud), cut it on one side in the same way as the nut in the previous subsection, put it on the stud, clamp it with a pipe wrench and unscrew it;
use a die (the one used for cutting threads), turning the end of the pin to a square of the desired size;
use a pin driver;
Using a hacksaw for metal, make a cut at the end for a flat screwdriver, with which you can remove the pin.

In some cases, if possible, to enhance the impact, simultaneously with applying force to a screwdriver or wrench, you can use a second tool (pipe wrench, pliers, etc.), clamping them on the smooth side surface and acting in the direction of unscrewing.

How to unscrew a broken hairpin

If the pin is broken and there is no part protruding above the surface, then you can unscrew it in the following ways:

using a semi-automatic welding machine, gradually and carefully “build up” a couple of centimeters (if the end of the stud is within reach welding wire) and remove the “growth” using a clamping tool;
use a special tool - an extractor (looks like a tap, the working part is conical, the direction of the thread is opposite to the thread of the stud): align the protruding end of the stud with a file (or saw off evenly with a hacksaw), tap exactly in the center, drill a hole along the axis of the stud required diameter and depth (approximately 2/3 of the length of the working part of the extractor), insert the extractor and rotate with force until the pin is unscrewed;
preparation with drilling as in the previous method, only use a tap on the left thread of the stud (if the stud is in the right direction) - when the tap, cutting the thread, rests on the bottom of the drilled recess in the body of the stud, the fragment is often unscrewed;
drill out the center of the stud, choosing the diameter in such a way as not to touch the threaded part of the socket, and then remove the remaining metal of the stud;
drill out the broken part of the stud and the threaded socket on drilling machine or hand drill a drill of larger diameter for the repair pin.

Using the method of drilling a recess and driving a Torx tip into it carries the risk of strengthening the wedge in the threaded socket due to the expanding deformation of the stud walls. Taking into account possible complications We will not recommend it in this situation, despite the fact that it is limited, with certain conditions, and it can be applied.

Aligning the end of the stud can cause difficulty if the breakage occurs in depth. In this case, an end burr will provide invaluable help.

Another variation for the drilling method. You can use drills with a left-hand direction of rotation and an electric drill with a direction switch and speed control. When drilling at low speeds, the wedged threads loosen and, due to the left rotation of the drill, the rest of the stud easily moves out of place and comes out of the threaded socket.

Drilling is often wiser to do in several passes, from small drill to those that are larger, to the required diameter.

How to unscrew a stuck hairpin

A soured pin must be unscrewed using additional tricks, both in terms of tools and in terms of methodology.

Apply several blows with a hammer to the end of the stud along its axis without damaging the edge of the thread;
apply several gentle blows from different sides to the side surfaces of the stud (at the same time screw a nut onto the threaded part to avoid damage), without allowing it to bend;
apply special penetrating compounds - WD-40, liquid key and their analogues, giving the necessary time in accordance with the instructions for these drugs from their manufacturer before attempting to unscrew;
use an extension to the hand tool to increase the applied force (longer wrench or putting a pipe of a suitable diameter on the rotating end hand tools;
do not use when unscrewing a welded nut open-end wrench, but a Super Lock head, in which the force is applied not to the corners (edges), but to the planes;
instead of using physical force and hand tools, use an impact wrench (if you don’t have one in your home workshop, you can go to the nearest tire shop or car service center and deliver the part with the stuck pin there);
when using the method of screwing two nuts, screw the first one all the way with such great force that it cuts into the cylindrical part of the stud, and use the second nut not a standard one, but a self-locking one (this will allow you to use much greater forces, reducing the risk of unscrewing the nuts);
Heat it several times and let it cool, at the final stage heat it up and unscrew it.

Repeated heating is also indispensable for unscrewing studs mounted on special compounds - thread lockers.

When unscrewing a stuck stud by a welded or screwed nut, it is better to use a tool that is structurally stronger and more tightly covers the perimeter of the working surfaces of the nut, eliminating the licking of the edges:

6-point head instead of 12-point;
Super Lock head instead of the usual one;
ring wrench instead of an open-end wrench;
a crank instead of a ratchet.

How to remove a stud from an exhaust manifold

If a steel pin has become stuck in a steel or cast iron manifold, then you can heat it until the metal turns red, carefully using a gas torch, a gas burner from a can, blowtorch or other suitable equipment.

How to unscrew the stud from the exhaust manifold to prevent cracks in the cast iron? First of all, you cannot artificially intensively cool a cast iron part. In this case, you need to heat the collector itself, without touching the stud: the collector will warm up and rattle a little in the area of the threaded hole with the soured stud, and the difference in heating of the parts will further weaken the sticking.

How to unscrew a pin from aluminum part

Parts made of aluminum and its alloys should not be subjected to intense impact with a gas cutter or other powerful equipment due to the risk of parts melting or otherwise being damaged by the impact. high temperatures. IN in this case Can:

You can only heat the hairpin, and then not to the point of redness;
use a hot air gun (heat gun) to heat the aluminum part or use a blowtorch to a limited extent in a more gentle manner temperature conditions than a gas burner can provide.

How to remove a stud from an engine block

First of all, when choosing an approach, you need to proceed from the material from which the engine cylinder block is made. In the case of a cast iron block, we use an approach with intense heating until reddening gas burner. If the block is aluminum, then in the area of the coked stud we carefully heat it with a hot air gun, avoiding damage to the expensive part from high temperatures.

For example, it is often very difficult to unscrew a pin from a ZMZ 402 engine block. It is characterized by systemic problems with unscrewing certain studs due to the material of the block and the characteristics of its heating during operation.

Several cycles of heating and gradual cooling will make it much easier to unscrew the stud from block 402. Recall that unscrewing the stud is carried out in a heated state. It will also be very useful to impact the stud - along its axis or loosen it with blows on the sides from different sides.

We outlined how to unscrew a broken pin from a block above in a separate subsection; the techniques for this part are not original.

How to unscrew a stud from a cylinder head (cylinder head)

When deciding how to unscrew a stud from a cylinder head, you must also take into account the material of the head. Cast iron heads are rare, mostly on old cars, and most often they are from aluminum alloys.

On block heads you often have to deal with stuck, soured studs.

To unscrew the stud from the cylinder head, you can use the most convenient and effective ways and the techniques listed above. This is often the two-nut method, using an extractor, or drilling. To enhance the impact, it is more advisable to use preliminary loosening tapping on the sides, the use of penetrating compounds, and rotation with two tools.

Conclusion

When faced with the question of how to unscrew a stud from a block, head, manifold, starter, wheel hub or other part, you can choose effective solution tasks from several methods and techniques, taking into account available tools and means. Both plumbing tools available in almost any garage and specialized ones, such as a pin driver, can be used.

Before unscrewing the pin, it is worth applying a shock to it. Also, if the threaded socket in the part is through, and the end of the stud sticks out, then the visible part of the thread should be cleaned of dirt, which can create additional difficulty when unscrewing. The preliminary application of penetrating compounds also facilitates the extraction operation.

How to unscrew the pin? Let's consider several methods, taking into account the condition of the stud and the available tool.

How to unscrew a stud by its threaded part

If the stud is long enough and a threaded part for 2 or more nuts is available, then we use one of the following methods:

screw on the nut, screw the second one all the way into the first one (it is advisable to use tall nuts), then unscrew the stud with a mechanic’s tool (wrench or other);
use a special tool - a hairpin driver, suitable for the size of a hairpin or a universal one.

An eccentric pin driver is convenient and effective - the greater the force applied to it, the stronger it clamps the pin with the eccentric notch.

How to unscrew a stud if there is only thread available for 1 nut? In this case, at least 4 methods are available:

cut the nut on one side with a hacksaw (the direction of the cut is along the axis of the threaded part), screw it onto the stud, clamp it with a pipe wrench so tightly that the threaded part, choosing a gap in the cut, tightly grips the stud, direct the force in the direction of unscrewing;
screw the nut onto the thread, weld it to the stud (for example, with a semi-automatic welding machine) and unscrew it with a wrench (or a head with a knob);
screw the nut onto the thread, drill a recess in the end of the stud (approximately half the diameter of the stud), drive a TORX socket (E-profile, or another similar one with longitudinal ribs) into this recess and unscrew it by the shank of the socket (you can use your second hand to help with this) with an open-end or socket wrench applying force to the nut in addition to the main force on the torx);

In the screwdriver method, a large version or a power version with a T-handle is better suited for this purpose.

How to unscrew a hairpin by its smooth cylindrical part

If only the smooth part of the stud is accessible (for example, the threaded part is broken), then the following techniques are applicable;

clamp the cylindrical part in a suitable tool (pliers, a pipe wrench, a small vice, a clamp, or the like) and apply force in the direction of unscrewing;
weld a metal rod to the broken end by welding as a T-shaped handle;
put on a nut of a slightly larger diameter, weld it to the stud in a circle and unscrew it with a wrench;
use a square washer as thick as a nut or more, with an internal diameter the same size as the diameter of the cylindrical part of the stud (ideally, if the washer fits on the cylindrical part of the stud with interference), cut it on one side in the same way as the nut in the previous subsection, put it on the stud, clamp pipe wrench and unscrew;
use a die (the one used for cutting threads), turning the end of the pin to a square of the desired size;
use a pin driver;
Using a hacksaw for metal, make a cut at the end for a flat screwdriver, with which you can remove the pin.

How to unscrew a broken hairpin

If the pin is broken and there is no part protruding above the surface, then you can unscrew it in the following ways:

using a semi-automatic welding machine, gradually and carefully “build up” a couple of centimeters (if the end of the stud is within the reach of the welding wire) and then unscrew the “build up” using a clamping tool;
use a special tool - an extractor (looks like a tap, the working part is conical, the thread direction is opposite to the thread of the stud): align the protruding end of the stud with a file (or saw off evenly with a hacksaw), tap exactly in the center, drill a hole of the required diameter along the axis of the stud and depth (approximately 2/3 of the length of the working part of the extractor), insert the extractor and rotate with force until the pin is unscrewed;
preparation with drilling as in the previous method, only use a tap on the left thread of the stud (if the stud is in the right direction) - when the tap, cutting the thread, rests on the bottom of the drilled recess in the body of the stud, the fragment is often unscrewed;
drill out the center of the stud, choosing the diameter in such a way as not to touch the threaded part of the socket, and then remove the remaining metal of the stud;
Drill out the broken part of the stud and the threaded socket on a drilling machine or with a hand drill with a drill of a larger diameter for the repair stud.

Using the method of drilling a recess and driving a Torx tip into it carries the risk of strengthening the wedge in the threaded socket due to the expanding deformation of the stud walls. Taking into account possible complications, we will not recommend it in this situation, despite the fact that it can be used in a limited manner, with certain conditions.

Aligning the end of the stud can cause difficulty if the breakage occurs in depth. In this case, an end burr will provide invaluable help.

Drilling is often wiser to do in several passes, from a small drill to larger ones, to the desired diameter.

How to unscrew a stuck hairpin

A soured pin must be unscrewed using additional tricks, both in terms of tools and in terms of methodology.

Apply several blows with a hammer to the end of the stud along its axis without damaging the edge of the thread;
apply several gentle blows from different sides to the side surfaces of the stud (at the same time screw a nut onto the threaded part to avoid damage), without allowing it to bend;
apply special penetrating compounds - WD-40, liquid key and their analogues, giving the necessary time in accordance with the instructions for these drugs from their manufacturer before attempting to unscrew;
use an extension to the hand tool to increase the applied force (a longer wrench or by placing a pipe of a suitable diameter on the rotating end of the hand tool;
When unscrewing a welded nut, use not an open-end wrench, but a Super Lock head, in which the force is applied not to the corners (edges), but to the planes;
instead of using physical force and hand tools, use an impact wrench (if you don’t have one in your home workshop, you can go to the nearest tire shop or car service center and deliver the part with the stuck pin there);
when using the method of screwing two nuts, screw the first one all the way with such great force that it cuts into the cylindrical part of the stud, and use the second nut not a standard one, but a self-locking one (this will allow you to use much greater forces, reducing the risk of unscrewing the nuts);
Heat it several times and let it cool, at the final stage heat it up and unscrew it.

Repeated heating is also indispensable for unscrewing studs mounted on special compounds - thread lockers.

6-point head instead of 12-point;
Super Lock head instead of the usual one;
ring wrench instead of an open-end wrench;
a crank instead of a ratchet.

How to remove a stud from an exhaust manifold

If a steel pin is stuck in a steel or cast iron manifold, then you can heat it until the metal turns red, using a careful gas torch, a gas torch from a spray can, a blowtorch or other suitable equipment.

How to unscrew a pin from an aluminum part

Parts made of aluminum and its alloys should not be subjected to intense impact with a gas cutter or other powerful equipment due to the risk of parts melting or otherwise being damaged when exposed to high temperatures. In this case you can:

You can only heat the hairpin, and then not to the point of redness;
use a hot air gun (heat gun) to heat the aluminum part or use a blowtorch to a limited extent in a more gentle temperature regime than a gas burner can provide.

How to remove a stud from an engine block

First of all, when choosing an approach, you need to proceed from the material from which the engine cylinder block is made. In the case of a cast iron block, we use an approach with intense heating until reddened with a gas burner. If the block is aluminum, then in the area of the coked stud we carefully heat it with a hot air gun, avoiding damage to the expensive part from high temperatures.

We outlined how to unscrew a broken pin from a block above in a separate subsection; the techniques for this part are not original.

How to unscrew a stud from a cylinder head (cylinder head)

When deciding how to unscrew a stud from a cylinder head, you must also take into account the material of the head. Cast iron heads are rare, mostly on older cars, and most often they are made of aluminum alloys.

On block heads you often have to deal with stuck, soured studs.

To unscrew the stud from the cylinder head, you can use the most convenient and effective methods and techniques listed above. This is often the two-nut method, using an extractor, or drilling. To enhance the impact, it is more advisable to use preliminary loosening tapping on the sides, the use of penetrating compounds, and rotation with two tools.

Conclusion

When faced with the question of how to unscrew a stud from a block, head, manifold, starter, wheel hub or other part, you can choose an effective solution to the problem from several methods and techniques, taking into account the available tools and means. Both plumbing tools available in almost any garage and specialized ones, such as a pin driver, can be used.

Repairing a car is far from the easiest process, and it doesn’t matter what brand the car is or what year it is made. All cars are subjected to serious loads every day, which means breakdowns are inevitable. The average motorist can easily fix most of these faults in a garage, working slowly and carefully. If you are careless when it comes to car repairs, you can often complicate the situation.

It so happens that in the process repair work When tightening or unscrewing bolts and studs, the threads break off. This is very unpleasant, especially if there is no knowledge of how to unscrew a broken pin. This situation confuses any repair. Let's try to figure out how to get out of this unpleasant situation.

Often fasteners break if the craftsman is large and has great physical strength, and the pin is stuck or rusted to the thread. It's about not about those cars that have just rolled off the production lines. Very often, owners of old cars that were stored and operated carelessly face similar problems. And to be even more specific, most likely such a machine was stored in places with increased level humidity. Chassis parts - studs - are almost constantly in contact with water. Therefore, it is not surprising that these elements rust. As a result, the owner is wondering how to unscrew the broken stud from the hub.

However, the fasteners do not unscrew and break not only due to moisture, but also due to high temperatures. For example, the exhaust manifold can be heated up to 400 degrees. As a result of exposure to high temperatures over a long period of time, the stud corrodes.

How do studs break?

These fasteners can break in different ways. The most unpleasant situation is when they are cut off literally flush. Then the master has to think about how to unscrew the broken pin, because in this case it is impossible to do without the use of special tools and technologies.

It is much better if the part breaks already at the exit from the thread, when a small part of its “body” will be visible and remain on the surface. In this case, if the bolt has already been torn off, it will turn out and can be manipulated with pliers, screwdrivers and welding.

Effective ways to deal with broken bolts and studs

Professional locksmiths know several effective methods How to unscrew a broken pin. Before you start this task, you need to prepare. By these works we mean cleaning the surface from dirt and grease. Threaded connection It is recommended to pre-treat with WD-40 or ordinary machine oil. You can also ease the situation by hitting the piece of wood with a hammer several times. Often the problem is solved by heating - the pin or bolt, provided that it looks out of the hole, is heated with a soldering iron. Then it can be removed relatively easily.

How to unscrew a stud if it breaks above the thread

If in the process it was possible to break the thread even a little, that is, if fastener started to turn out, you can try using pliers or pliers. A good and powerful one will also help in this difficult task. In the second option, you may also need a grinder. Sometimes a chisel will do just fine - the main thing is not to use excessive force. How to unscrew a broken wheel stud this way? Make a transverse hole for a screwdriver and unscrew the pin with this tool.

If a screwdriver does not help, then you can use this operation. This operation is quite easy. Prepare a bolt whose head approximately corresponds to the diameter of the stud. Next, the bolt is welded to the fragment protruding from the hole. Then, using the key and without extra effort They try to unscrew the unfortunate pin. Experienced auto mechanics say that there are special adhesives with aggressive action that can be used as cold welding. But they are not always effective.

If the pin breaks below the surface or in the hole

In this situation, you will need a drill, a thin drill bit for it, as well as good tool skills. Before unscrewing the broken pin from the engine block, it is necessary to drill 2-3 or more thin holes in the body of the pin. Then these holes will have to connect into one single hole. They insert a screwdriver here and try to unscrew the broken pieces of the bolt.

Left-hand thread in stud

The second method is more difficult. It is used when it is impossible to unscrew a broken pin using any of the available ways. In this case Taken measures will be even more dramatic. For this method you will need electric drill, a tap and a lot of time. First of all, a hole is drilled in the stud - right in the center. Then carefully cut the thread in the hole with a tap.

Note important point: before unscrewing the broken pin from the head, make sure that the thread is “left-handed”. When a new bolt with the same thread is screwed into the newly cut part, the moment it reaches the end, the broken pin will begin to turn out.

Drilling

And finally, the third and most radical way. It is used to remove broken bolts and studs from the hole. This is drilling. The method is very difficult. It is much more complex than all of the above and is the most dangerous. There is a risk of damaging the threads in the bore of the engine block or cylinder head. You should hold the drill securely, as if you do this, there is a serious risk of damaging an expensive part. The hairpin is often made from more durum varieties steel, and the head is made of aluminum. The commutator body is cast iron, so it is also softer than a steel stud. The drill will definitely move away from the hard stud and towards the softer metal. This happens especially often if the work is carried out in limited space, and the drill is installed at a slight angle. The principle of drilling is as follows: you need to make a hole strictly in the center of the stud with a thin drill, having previously cored it, then install a thicker one in the drill and repeat the entire procedure.

The main thing here is to drill strictly in the center. When practically nothing remains of the stud body, the wall will become thin. It can be broken. You should very carefully break off the remaining pins using pre-sharpened wire or tweezers. It must be remembered that any action is carried out as slowly and carefully as possible. If you act rashly, you will need to think not about how to unscrew the broken block stud, but also about how to restore the cylinder head itself. And these are significant costs.

We use a conductor

You can greatly simplify the operation of drilling out broken studs. This is relevant for those who often repair engines. A simple conductor will help the master. The dimensions of the part are taken from real engines. On the conductor, and this metal plate, the same holes are drilled in the same places as on the head, as well as on the manifold. Holes for bushings are also made in the jig. They will keep the part from moving on the block.

With the help of such devices, you can greatly facilitate the task and figure out how to unscrew a broken pin from the exhaust manifold by drilling without damaging the manifold itself.

Extractors

The extractor is special device, allowing you to remove remnants of faulty fasteners or unscrew a broken pin. The device is very simple and at the same time ingenious. In order to remove a stuck or broken part, you need to somehow hook it and then unscrew it. And all this is done very simply. You need to drill a hole in the center of the stud, wedge some tool in the shape of a cone or cylinder into it, then use this tool to remove the bolt. This is the extractor. These devices make it much easier to resolve issues such as unscrewing a broken pin from a manifold or from any other places.

There are several types of extractors:

Wedge-shaped.
Rod.
Spiral.
Screw.

These devices can now be purchased in sets, but they are also available individually. Experts recommend using these tools. They make solving difficult situations such as broken bolts much easier.

Choosing steel for the stud

Often auto mechanics make their own studs. They recommend making these fasteners from the following grades of steel: 35, 40, 45, 50, 55, 60. If you make a new fastener from this metal, the result will be a product with sufficient tensile strength.

If the studs will be purchased in stores, you should not choose the cheapest ones or those that you saw on the counter of a car store. The most reliable products have a part number - 13517010. The penultimate number indicates that this stud has sufficient tensile strength.

Before screwing in the stud...

So that you don’t have to think about how to unscrew a broken pin, before getting to work, it is recommended to lubricate the part with graphite, or better yet, let the element unscrew together with the nut rather than break. And finally, it is also better to treat the nut threads with graphite lubricant. In the future, this will prevent the part from breaking or breaking.

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