How To Oil An Impact Wrench

by Joost Nusselder | Updated on:  March 12, 2022
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Having an impact wrench can save a lot of time and energy in any of your mechanical work. Most of the impact wrench is powered by electricity or air. When you buy an electric impact wrench, there will be no moving parts as the motor is sealed inside. But an air impact wrench has moving parts that need oiling to lessen friction and smooth rotation. If you find your air impact wrench not performing as well as before, you must think of lubricating the moving parts in the impact wrench.
In this article, we will articulate the whole process of how to oil impact wrench so that you can ensure durability and smooth performance of your tool.

Parts Of The Impact Wrench That Need To Be Lubricated

Before we tell you the step by step process of lubricating your impact wrench, you must know which parts of the wrench you need to oil. In an air impact wrench, there are only two moving components that need to be lubricated. Those two moving parts are:
  • The motor and
  • The impact mechanism/ The rotating hammer.
Now, most of you know what a motor is. It basically converts air energy to mechanical force in linear or rotatory motion. In an air impact wrench, it gives power to the impact mechanism or the rotating hammer so that it can rotate the anvil for tightening or loosening the bolts.

Types Of Oil You Need For Lubricating The Impact Wrench

Both the motor and rotating hammer mechanism work independently and require separate lubrication. For oiling the motor, you must put any airline lubricator or air tool oil. To apply the oil, you must have an air tool that you will find in any impact gun manufacturer. However, to lubricate the impact mechanism, motor oil is definitely an ideal option.

How To Oil Impact Wrench- The Process

Dismount The Impact Wrench

Before you oil your impact wrench, it’s highly important for you to clean the wrench first. Because an impact wrench comes lubricated when you buy it. And after using it for some time, dust and other metal particles will get stuck with the moving parts that need to be cleaned up. If you apply oil without cleaning up the accumulated dust, you won’t see any results of oiling the gun. Therefore you must disassemble the impact wrench. The process you must follow is:
  • Put off the rubber case wrapped on the metal body of the wrench so that you can see what’s under it and get access to every point.
  • After that, remove the rear part that is attached more likely with 4mm allen bolts in order to get access to the inside of the wrench.
  • When you pull off the back part, you will see a gasket there. To open the gasket, there will be an alignment rod that you need to pull out to remove the front bearing.
  • After removing the front bearing,  retreat the air motor from the housing.
  • Pull out the housing components too.
  • Lastly, you will have to disassemble the hammer with the anvil by just pressing the front of the anvil with an iron rod or hammer.

Clean the Disassembled Components

After separating all the parts, now it’s time for cleaning. With a brush dipped in spirit, rub off all the metal rust and dust from each component and especially from the moving parts. Don’t forget about cleaning the motor vane.

Assemble all the Components

When cleaning is done, you must assemble all the components together back in place. For assembling, you must be very careful about the position of each part and the chronology. That’s why be very careful while detaching the components so that you can maintain the order when you will require to assemble it again.

Lubricating the Wrench

Oiling the impact wrench is the easiest part of the whole process. As we have said there are two parts that require lubrication. You will find an oil inlet port on the side of the wrench to start off.
  • First of all, using a 4mm key, remove the screw of the oil inlet port to get access to the hammer mechanism.
  • Using any tool like a 10 ml syringe or dropper, squirt one ounce of motor oil into the oil inlet port.
  • Reinstall the screw nut back in place with the Allen key.
  • Now put 8-10 drops of air-oil into the air inlet port which is located underneath the wrench handle.
  • Run the machine for a few seconds which will spread the oil all over the machine.
  • Then you will have to remove the oil plug to pour all the excessive oil that can accumulate extra dust particles and clog the air motor.
  • Clean the impact wrench body and put on the rubber case you took off earlier in the process.
That’s All! You are done with oiling your impact wrench for smooth and precise operation.

Things You Must Remember

  • Type of the Impact Mechanism
Basically, there are two types of impact mechanisms; the oil impact mechanism and the grease impact mechanism. Read the manual of your impact wrench that was provided by the manufacturer to find out which impact mechanism your impact wrench has. If it is a grease impact mechanism supported wrench, squirt grease only into the contact point of hammer and anvil. Don’t put the grease all over the machine. If it’s an oil system-supported tool, you are good to go with our suggested lubrication process.
  • Frequency of lubrication
You must lubricate the impact wrench after a definite time period. Otherwise, there is a higher possibility of getting damaged by clogged dust and metal rust. For the grease impact mechanism, you are recommended to do regular replenishing. Because, due to the friction, the grease vapor real quick. Therefore, it requires frequent lubrication.

Frequently Asked Questions (FAQs)

When should I oil my impact wrench?

There is no such definite time period for lubrication. It basically depends on the frequency of using the tool. The more you use it, the more oiling is necessary for smooth operation.

Why is the lubrication of the impact wrench necessary?

Basically, lubrication is needed for lessening the friction at the contact point of the hammer and anvil to ensure the motor’s and machine’s durability.

Bottom Line

To get a perfect and balanced output all the time from the impact wrench, lubrication is a must. It also prolongs the durability and effectiveness of the tool. Therefore, whether you are a professional or a hobbyist who uses an impact wrench for different purposes, you need to maintain a lubrication calendar. Thus they can ensure perfect timing for oiling the wrench and enjoy the ultimate performance from the tool. Hope all the processes articulated in the article on oiling your impact wrench will be enough for you to start the lubrication.

I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.