Ultimate Guidelines in Repairing a Cordless Impact Driver

Impact Driver Structures Quick Guide

A cordless impact driver comes with varying mechanisms that help it operate and function. This tool is more preferred compared to a cordless drill driver because this is more compact, small and lighter in weight. In addition, they are much more powerful with minimal kickback force. A lot of professionals prefer to use this type of tool when working with heavy-duty projects. With this tool, heavy projects can be performed easily.


The Impact Driver Includes 4 Main Parts

1. Bit holder: it is the part connecting and holding the bits

Bit holder of Impact driver

2. Hammer: it is part making force to driving the tool and tightening or loosening a screw.

3. Motor: this part is making driven for the hammer.

4. Housing: This is body include to connect the battery, and keep all electric part.

In this article, I give you how to repair each part mechanisms above of impact driver. And repairing the electric part I will do with another article.

When repairing a cordless impact driver, there are several steps that you need to follow. Here are the steps to repair a cordless impact driver:

How To Repair Impact Driver

Things You Will Need

After this, you have to prepare the required tools that you will likely use during the maintenance. You have to prepare;

1. The equipment extractor.

2. Screwdriver magnetizer.

3.  Center connection.

4. Retaining band S and R pliers.

5. Torque wrench shaft measuring 20-90N.M.

6. Socket wrench 30-78mm.

7. Grease

Apply the prescribed oil on designated areas of the tool. These areas are typically marked with a dark triangle. The oil protects parts of the tool from possible abrasion.

Step By Step

The first thing that you need to do is to remove the battery pack from the device. This is for your safety while repairing and maintaining the device.

The Bit Holder Section Of The Device

When it comes to the bit holder section of the device, assembling and disassembling steps should be followed;

When disassembling the bit holder section, you should first remove the ring springtime from the groove on the Anvil using the retaining band S and the R pliers. Then, the flat washing machine, the sleeve, the compression planting and the metal ball 3.5 can be removed.

When assembling the device, you should do the disassembling steps backward. Lastly, you should apply grease to the Anvil before placing the outer through it.

The Hammer Case

When maintaining the hammer case, you need to disassemble it by taking away the bit holder area. Then, eliminate the PT3x10 tapping screw and remove the draw LED out of its casing before detaching the stopper. After, you can remove the bumper from hammer portion of the device. Switch the hammer clockwise to completely disassemble it.

In assembling this portion of the device, do the previous steps backward. Also, you should never forget to place the O band 46 inside the groove located in the inner equipment case. In fastening the internal gear, you should turn the gear counterclockwise towards the torque using a 30-40 N.M tool.

The Housing Section

In disassembling the Housing L or Casing R motor section, you have to remove the components until the internal equipment case is totally exposed. Eliminate the carbon brushes before removing the four M4x12 screws that fasten the case to the Housing R and Casing L. A thread locker is placed on the screws.

After, unscrew eight PT3x16 tapping screws to remove the internal gear case. During this time, the housing R can be separated from the casing L. Moreover, the internal electric parts can be removed from Housing. You can now remove the engine section from the casing L before you can remove the end bell from the armature. After, you can place the motor area on the function table. Then, separate the yoke device from the armature through pulling it down to the task bench.

In assembling this part of the device, you have to make sure that the notch within the Yoke device is placed on the drive finish of the armature. If this is set up incorrectly, the engine part cannot be set up to the housing. You should assemble the rubber pin 4 to both the casing R and the housing L and make sure that the pins are in place before placing the housings.

The Hammer System

The next thing to deal with is the hammer system and the spindle section. In disassembling this part, you have to remove the hammer first. You can do this by pressing down the sludge hammer fully using a gear extractor. Then, you have to switch the spindle handle in the opposite direction and remove the metal balls from the spindle using tweezers or using a screwdriver magnetizer.

In assembling this part of the tool, you have 3.5 metal balls in the groove on the hammer. After this, you can do the disassembling steps in reverse to assemble this part of the device.


Impact drivers are one of the best tools to use today. Such type of tools offers higher torque at a much faster speed. This can be compared to a hammer with exceptional linear power. This tool is ideal for heavy-duty work like driving lag bolts. Despite its power, this tool might be difficult to control because of its knocking motion. If this tool fails, you simply have to follow the steps provided above to repair the tool easily and swiftly.

You can see this video for clear this work:

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Jose A. Brown

Jose A. Brown is a mechanic engineer and an enthusiastic blogger whose mission is to provide the readers with the best tips, guides in the Home Improvement, DIY Project, and Industry.

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