How To Install and Remove Cotter Pin [Types of Cotter pin]

Cotter pins are important components in your vehicle’s system used to secure bolts or any other type of fastener. These cotter pins are placed into bolts to prevent in from getting loosed or coming out. It is quite common for bolts in your car system to wear off with time, especially bolts attached to vibrating parts of your vehicle. The cotter pin is one of those tools used to keep your bolts in place. Therefore, knowing how to install a cotter pin is amongst essential automobile DIY skills to acquire.

Properly fixing your vehicle’s cotter pins prevents the loosening of other parts and also stop CV joint noise. Cotter pin, sometimes called a split pin, is of different types, which you will later get to know as you progress in reading this article. You need to take note of this installation process if you usually work with structural or machinery assemblies. This video can also be of help.

How To Install Cotter Pin: A Step-By-Step Guide

We will go over now the correct way to install a cotter pin in your suspension system. Most people do this wrongly a lot of times, and every time we go in for a wheel alignment on vehicles, we notice that a part of the cotter pin is awkwardly bent. I’m afraid that’s not right, people. Very wrong! It is a very simple repair, one of the easiest automobile repairs out there. Although even if you do it wrong, it is going to work as designed.

But it’s not always the fact that you can do it. I mean, if you are twelve years old and you get something done, you will be like, Hey! Look, Man, no hands. You know, you can be proud, but as you progress as a mechanic, you also want to be proud of doing things right and doing things better. Ten years of experience does not mean shit if you have ten years of experience doing something half as or wrong.

We have not seen any other article that has talked about this topic, in particular, so we are going to be the lame duck that writes this article because it is somehow annoying that people do not do this right. With this process, a special cotter pin installation tool might not be needed.

So when you look at a cotter pin, did you ever notice that right on edge there, you got that little part of the cotter pin that’s notched out, where one’s shorter than the other side. You think the manufacturers do that for their health or because they are trying to save our metal times two million cotter pins. No! They are not. They are doing that for leverage. When you install a cotter pin, you want the longer side to go up. Ok! And we are going to show you this.
Continue reading this article to know how to remove a cotter pin; for people who don’t know how to do this. It’s also an easy process. All you need to do is follow the guide.

Now when you go to put your cotter pin in, seeing though you have already lined everything up so that you are in a good position to remove it next time. It’s nice to have the hole parallel with the spindle, or at least depending on your situation. You want the hole in an ideal way for future cotter pin maintenance.

So take your cotter pin and put it inside the designed hole. When you put it in there, make sure you have that longer side up.

The reason is when you go to set your split cotter pin. Now you can get your finger under one side. And you can easily push it over its housing.

Most automobiles don’t use a ring cotter pin, so it is not complicated to do. Please do not bend both sides of the cotter pin. That retarded shit, it’s going to make it much harder to get it out. Especially when it starts getting rusty and after it has been in there for a while. Hardly anybody knows this trick, but this is how you are supposed to do it. That’s why the notch is there. When you take out the pin, you will only have one of them to bend back.

The other one’s straight, which is already going to make it easier to yank out, and I can use my vice grips, and when I bend the other side out, I can squeeze the tube together, and the straight one is going to serve as a guide to straighten the other one out. If you don’t do this well, you might begin to have issues with your brake system.

It’s that simple, folks, and that is the proper way that you install a cotter pin. This method can also be used in aviation cotter pin installation.

What Is A Cotter Pin Used For?

A cotter pin is a metallic pin used as a fastener for locking nuts into bolts. You can use this pin by creating small holes in the bolts or other fasteners. Clevis pins, a different type of fastener, are commonly used with cotter pins because they have already made holes in them.

Cotter pins are used for many applications, including locking nuts into place and getting rid of steering noise. They are made of mild steel, which means they are durable. Cotter pin, also known as a split cotter pin, is made up of harder grade steel. A split pin comprises two long spikes that are bent to hold it in place. Other types of pins like Hairpin cotter pins or clips are made to slip on without any bending problem.

In other words, a cotter pin is an uncomplicated fastener that is used to secure a bolt in its place. Comprising of a U-shaped piece of metal, inserted through the hole of a bolt, with its ends twisted together.

Cotter pin serves as a locking mechanism, and it is used in different situations. For use, it requires nothing more than a bolt and a hole in it or a drill. Cotter pin sizes differ, so do their uses.

Though not considered necessary for installation, but are necessary depending on the application. A motorcycle’s front wheel is usually held together by a castle nut and a cotter pin subjected to frequent vibrations. Cotter pins use their strength to provide a very strong and reliable locking mechanism. But are cotter pins one-time use? Well! They should not be reused because the extra bending weakens the pins and produces a failed result when used.

Split pins are used for many installations and act as a quick locking mechanism that is very easy to remove and replace. Still, the main benefit is that they will help prevent the nut from getting loose irrespective of vibrations.
A locking cotter pin is done by inserting it into the bolt’s hole until the head of the pin is resting against the bolt.

Spread the prongs in opposite directions to secure the cotter pin, using pliers if needed. Using diagonal cutters to cut the excess length of either prong, according to your knowledge of application, is one of the many ways to use cotter pins.

Cotter Pin Types And Sizes

Cotter pins comprise of different types and sizes. Bicycle cotter pin sizes are slightly different from automobile cotter pin sizes, so they cannot be interchanged. The American standard for cotter pin sizes starts at 1/32. Sizes below 5/16 inch are made to fit a hole of 1/64 inch larger than the pin’s size. For pins larger than this, the pin and hole are of the same size. For cotter pin length selection, these cotter pin sizes metric are drafted below.

Cotter pin sizes:

  • 1/32 inch
  • 3/64 inch
  • 1/16 inch
  • 5/64 inch
  • 3/32 inch
  • 7/64 inch
  • 1/8 inch
  • 9/64 inch
  • 5/32 inch
  • 3/16 inch
  • 7/32 inch
  • ¼ inch
  • 5/16 inch
  • 3/8 inch
  • 7/16 inch
  • ½ inch
  • 5/8 inch
  • ¾ inch

Note that the drill size for cotter pins in bolts or any fastener should be almost equivalent to the cotter pins’ size to be inserted into the hole. You cannot use small cotter pin sizes for large drilled holes.

For Cotter pin types

  • Split pin:

It is a metal fastener that has two spikes or tines that are bent during use for installation as a tool to fasten metals together, use resembling that of a staple or rivet. Split pin sizes range from 1.19mm to 19.05mm

  • Hairpin cotter pin:

Commonly known as an R-clip are used without the need to bend for usage.

  • Bowtie cotter pin:

It is vibration-proofed and also a type of R-clip that is shaped like a bowtie.

  • Circle cotter:

It is a ring-shaped cotter pin.

  • Cotter (pin):

It is passed through holes of a bolt to make parts fit tightly together.

  • Clevis pin:

A type of fastener that allows rotational movement within the axis of the pin of the object connected to it. This type of pin consists of a shank, hole, and head. The hole drives through the shank at the opposite side of the pin. Usually, the clevis pin is used in conjunction with a shackle.

  • Dowel pin:

“It is used as a location guide for adjacent mechanical components and keeps the two sections of punch and dies in sync. Hardened and purpose shaped dowel pins are in keeping machine parts in absolute alignment”.

  • Taper pin:

“A taper pin is a steel rod used in mechanical engineering for fastening. They have slightly larger diameters at different ends”.

  • Groove pins:

Grove pins are cylindrical, with three longitudinal grooves, made from bar or coil stock.

  • Knurled pins:

This type of cotter pin is a typical roll formed pin with normal diameters from 3/32-3/8.

  • Wire snap cotter pins:

These are used in clevis pins or shafts to keep components arranged in one place.

  • Hammer set cotter pins:

They are hit with a hammer after insertion for a temporary hold.

  • Wedge lock cotter pins:

Place this heavy pin inside the hole in a clevis pin. After insertion, you a hammer to open up prongs for stronghold.

How To Remove A Cotter Pin

Removing a cotter can be easy or quite difficult depending on how the pin was installed at first and if the hole is thick and rusty. It is quite different from how to remove a cotter pin motorcycle.

How To Remove A Cotter Pin

What you should do first is to put on your safety gear even if you are using a 4 post car lift. Gently detach your axle nut from your wheel. You need to use the right socket size for this. If not, you might end up spending more time than needed in taking-off your axle nut. Then use your socket or lug wrench to give your lug nuts a quarter turn. Please make sure that your vehicle’s emergency brakes on and your wheels are chocked.

When unscrewing axle or lug nuts. Most times, so much effort is required to get the nuts loosed, so you need to ensure your vehicle is firm for this process. That’s why you must engage your brakes and chock your wheels before unscrewing any of the nuts.

Some vehicles’ wheels are designed with a hubcap to protect the lug and axle nuts from getting moist or accumulate debris. If your vehicle has this hubcap, you will have to remove it to access your axle and lug nuts. You can pry off the hub cap with a screwdriver’s flat end.

When you have your axle nut taken-off, your axle nut, and loosen your lug nuts a little bit, you can raise that side of your vehicle you need to work on. A 3-ton floor jack or car lift can be used to lift vehicles and use whichever tool you have proper knowledge of. You also need to peruse the manufacturer’s guide to know the right positions to place the jack and jack stands and the car lift’s adaptors.

Now that your vehicle is lifted to a moderate height. You can now take-off the whole of your lug nuts and remove your wheels from your axle. You do not need to raise your vehicle too high; this is because you will not be working under your vehicle, so a moderate height is needed for a cotter pin removal process. Suppose you are using a car lift. Raise your vehicle to a comfortable height that will enable you to see your cotter pin area.

Now that you have gotten to your cotter pin area, you will see both sides of your cotter pin. This is just like how to remove a rolling pin. Use any of the right pliers to straighten out the bent side of the cotter pin. You need to use a gentle effort for this process. You don’t want to use your plier to overly bending your cotter pin; it will make the whole process more difficult to pull off. This is why you need to use the method suggested above when installing cotter pins; it makes the removal process easier.

Once you have gotten that part of your cotter pin all straightened up, use your side cut or dikes to grip the other end of the cotter pin, more like the illustration below.

And then use your pliers to yank off the pin, if the pin is proving hard to yank off you can hit the pin with the plier. After a few hits, the cotter pin will slide out from its hole. You can use a cotter pin removal tool for quick removal. Easy right! This process is even easier when the cotter pin is installed the right way.

If hitting with a plier is too stressful for you to use, a cotter pin press is another option to consider that can easily remove your pin.

Final Words

The cotter pin installation and removal process are very easy as long as you know the right steps to follow. Hopefully, this article on how to install a cotter pin has given you a concrete knowledge of what you need to know about cotter pins. We are sure you can now do this on your own. However, let us know what you think.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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