When a pulley is mounted on a keyed shaft, the key prevents the pulley from coming off in most instances. Sometimes, however, it’s necessary to remove the pulley for maintenance or repair. If the pulley has a split nut rather than a standard nut and bolt fastening system, you cannot simply unscrew it to remove it. You must find another way to get it off.
And if there is no other way to get the pulley off safely and without damaging the shaft, then you need to know how to remove a pulley from a keyed shaft without damaging either one. Fortunately, there are several ways of doing this successfully and cost-effectively.
Using a Puller and an Adhesive
One way to remove a pulley from a keyed shaft is to use a pulley puller and an adhesive. An adhesive is something that, once applied to the shaft, will stick to the pulley so strongly that you’ll be able to pull the pulley off the keyed shaft with little or no effort. You can buy an adhesive, such as Loctite, at most hardware or home improvement stores.
Most adhesive comes in a tube like toothpaste or a small can, like super glue. You’ll have to follow the instructions on the packaging carefully to get the best results. If you’ve never used an adhesive before, ask a hardware store employee to show you how to use it properly.
Using a Threaded Shaft Extension
Another way to remove a pulley from a keyed shaft is to use a threaded shaft extension. A threaded shaft extension is a piece of threaded steel rod that has been manufactured to the same diameter as the keyed shaft on which the pulley is mounted. You can find this type of threaded shaft extension at most hardware stores. A threaded shaft extension can also be referred to as a threaded bolt or threaded stud.
Using an Oscillation Tool
An oscillation tool is a power tool that spins a blade or nut around the edge of a metal surface to remove paint, rust, or other surface contaminants. A specialized oscillation tool blade, called a cut-off blade, can also be used to cut a keyed shaft off above the pulley so you can remove the pulley with a wrench. A cut-off blade can be used with many different oscillation tools. If you don’t have an oscillation tool, you can use a cut-off blade with an impact wrench instead.
Using Lockout Tools
A lockout tool is designed to grip onto a nut or bolt and prevent it from turning, even if you apply a lot of force to it. Lockout tools come in two main types: a locking pliers and a vice grip. Both types of lockout tools are designed to be used with an impact wrench. Some vice grips are also designed to be used with an oscillation tool. A lockout tool can be used to remove a pulley that’s mounted on a keyed shaft by gripping the bolt or nut of the pulley and preventing it from turning.
There are several ways to remove a pulley from a keyed shaft. If a pulley is mounted on a keyed shaft and you need to remove it, first make sure you understand why.
If you don’t, ask your supervisor to explain the reason. When you understand why the pulley needs to be removed, you’ll be able to determine which removal method is best for your situation.
The most important thing to remember when trying any of these methods to remove a pulley from a keyed shaft is to be safe. Don’t ever try to remove a pulley without wearing safety glasses and hearing protection. Also, make sure the area is well-ventilated and not in danger of sparking or catching on fire.