There are a number of times when working on your car or home that you end up messing up the threads on a bolt or spark plug or wind up with a nut that you strip the heck out of.
So what can you do in this situation other then grab a beer and start crying …..
Well in some cases you are going to endup replacing the item or bringing it to a machine shop to have a professional fix it for your but more often then not if you see the problem coming before its too late you can get yourself out of it with a few simple tricks and tools.
Selecting the right Wrench
The most important thing whether you are removing a spark plug or head bolt or axel nut is to select the right wrench for the job.
In many situations you want not only a wrench or socket that matches the size but often you are best off buying a special tool used just for that job.
For instance Spark plugs are one job that you should get a special socket and not rely on one of your deep sockets to remove the plug. Spark plug sockets have a rubber insert in the center of the socket to hold the plug in place when you are removing and installing it. This will help you not cross your threads and it will also reduce the chance you snap the ceramic neck of the plug.
Always use 6 Point Wrenches and Sockets on 6 Point Nuts and Bolts.
If you are removing a nut or bolt that has been torqued to spec or has rust on the threads always use the corresponding tool to remove it. If you use an open end hand wrench or a 12 point socket on a nut you are just asking for it to get rounded over.
Never Use Standard Sockets on a Impact Gun or Air Wrench.
You should always use thick walled sockets when using any type of air or electric wrench. Hand tools and normal sockets are used to remove nuts and bolts at hand speed. If you use a thin wall socket on a air wrench the socket will distort in shape under pressure even if the socket doesn’t crack it can still flex to the point it will strip the nut or bolt head.
Use penetrating oil and clean exposed threads.
When you are dealing with rusted or dirty parts you should use a penetrating oil and clean any threads with a Brass Brush not a steel one. Never use sandpaper or any abrasive that can destroy the fastener. Penetrating oil can take 12 hours to work so take that into account and you might want to hit your parts Friday night before you work on them Saturday.
Try tightening the nut or bolt to break it free.
Sometimes when you are fighting a fastener that has been rusted or torqued past spec you could endup slightly rounding the edges needed to loosen it as a last resort try tightening the bolt slightly to break it free from its mechanical weld and then backing it off. This often works on suspension parts and rusted fasteners.
So the nut is stripped what to do now?
Well if the nut is totally stripped and you have used a variety of sockets and wrenches to get it off but just can’t you might want to give a vice grip a try. Vice grip wrenches are spring loaded and can grab on to the nut even when it is rounded off.
Make sure the tool has a really tight grip and give it a shot. You may even want to apply some heat to the nut. A few hundred degrees should be enough you don’t need it to glow cherry red.
Heck you can even go crazy and weld the vice grip or even a wrench to the nut with a mig welder if you have one as a last resort.
Cutting the fastener off
So you just can’t get the fastener off the threads well now its time to just cut the thing off.
The way you approach removing the fastener is important. You do not want to destroy the part but a fastener that is fried will need replacing anyway.
You may want to try a commercial nut cracker. This tool will fasten around the nut and as you crank the handel a hardened chisel will attempt to crack the side of the nut open.
You might also want to drill into the nut to release pressure.
If you are removing a headbolt or another type of bolt where the fastener holds one part onto another part and the threads on the bolt are deep into the main part you can just cut the head of the bolt off or better yet drill the head off.
At that point you can remove the engine head and you will have a bolt shank sticking out that you can work with to remove from the engine block. Or you can bring the block to a machine shop to have it removed.
Fixing the Stripped threads
Ok the important part has passed you got the nut or bolt off and you are ready to replace it but before you do you need to inspect the threads on your part where your new fastener will attach.
If the threads are on a bolt or other removable item throw it away. If the threads are in a part like in the case of spark plugs or head bolts that fasten into the engine block you will need to chase and clean the threads.
A Tap and Die Set can be used to clean, chase and create new threads on fastening surfaces.
The Tap that looks something like a drill with groves is used on internal threads and the die is used on bolts and fasteners. These items are suppose to be used by hand and can take some time to clean up your fastening surfaces.
The Taps and Dies come in matching sets but if it is necessary to widen the threads in a fastener receiving hole it will also mean that you need a larger fastener.
Enlarging the fastener size could destroy the part. Engine blocks have specific specs and necessary wall thicknesses. It may be possible that enlarging a fastener opening could weaken coolant passages or other structures.
Helicoils
Helicoils have been used for some time to replace threads in parts.
The way they work is that you drill out the destroyed threads and then use a special tap to make a larger threaded hole.
Now instead of using a larger fastener you insert the helicoil into the hole. There are threads on the inside and outside of the helicoil.
This will allow you to reuse the original fastener size for the connection.
The working strength of the helicoil should match your application. ALWAYS check the torque rating for your fastener when using a Helicoil to repair threads.
Loctite also makes a liquid thread repair but be careful about using it in high torque conditions.
AND REMEMBER use anti seize compound when you replace your parts it will reduce this happening next time.
Final Note
Remember always destroy the Fastener when your part is in jeopardy. When in doubt bring the item to a machine shop for professional repairs. AND if the integrity of the part is weakened or out of safe use spec toss it and get a new one.
The YouRepair Store sells all the tools you need to Repair Threads and restore service to your parts.