The new impact drivers on the market, particularly the cordless impact drivers, have made a powerful impression on consumers. The overall improvement in performance, power, and reliability have made impact driver the tool of choice for many different tasks.
One potential use of impact drivers is removing lug nuts.
Can You Use a Cordless Impact Driver to Remove Lug Nuts?
The short answer is yes, but it depends. You can remove lug nuts of your car using an impact driver provided the nuts are tightened at the right amount of torque (80 to 100lb-ft) and your impact driver’s output torque is higher than 100lb-ft. In practice, however, rusted/frozen and over torqued lug nuts will not break loose with a cordless impact driver.
Given the power and durability of the new impact drivers, they seem like an obvious choice. However, they are not the right tool for the job.
Why an Impact Driver is Not the Right Tool
While technically an impact driver appears to be the right tool for the job, the problem stems from when the lug nuts are tightened beyond 100lb-ft. While the lug nuts of most car tires should be tightened or torqued from 80 to 100lb-ft, many are tightened to an even greater degree. Heavy automotive vehicles with large tires need to be torqued even higher. This means that a typical impact driver will have to face about 1500in-lbs (125lb-ft) in terms of torque which reaches the maximum limits of their capabilities.
However, while 100lb-ft of torque can be overcome by different brands of impact drivers, when there are additional obstacles removing them gets beyond their capabilities.
Any of these three events can hold a lug nut in place at far greater than 100lb-ft. This means that you will need to find another tool that can break loose the lug nuts so they can be easily removed by the impact driver.
Note: The amount of torque is expressed either in pound-foot (lb-ft) or inch-pounds (in.lbs). In the metric system, the unit of torque is newton meter (Nm).
Use an Impact Wrench to Break Loose the Lug Nuts
An impact wrench (or impact gun) is generally far more powerful than an impact driver. Some models are capable of delivering up to 220lb-ft of torque. Even the most stubborn of lug nuts will generally break free under that kind of power. This is true even when using some compact versions of impact wrenches. However, it is recommended that you use full-size, heavy-duty impact wrenches when dealing with stubborn lug nuts.
Read also: Do not get confused between these two power tools. In case you are, I suggest you read the difference between impact driver vs impact wrench here.
It’s generally a good idea to loosen lug nuts with an impact wrench or manually with a breaker bar or lug nut wrench that you have as part of your spare tire kit. Then use your impact driver to spin the nuts off. By putting your muscle into it first, it makes it that much easier for the impact driver to do its job later.
Make sure that the impact wrench is level so that you do not sheer off a corner when placing it over the lug nut itself. You can test the impact wrench before placing it on the lug nut to see if it is turning in the right direction. A little patience and double-checking may save you from over-tightening the lug nuts which causes further problems.
How Much to Torque Lug Nuts?
Generally speaking, you should torque lug nuts of your car wheels from 80 to 100lb-ft. This is tight enough to keep them from coming off, but not so tight that an impact driver cannot remove them. For those who are changing tires at home, if you are using an impact driver, you should tighten them until the driver stops and then perhaps give them one more tighten using a standard lug wrench.
The exact amount of torque for the lug nut varies for different manufacturers and model of your vehicle. For example, most of the BMW passenger cars the wheel nuts are torqued between 80 to 105lb-ft. In contrast, the wheels of a heavy-duty pick-up truck like For F-350 DUALLY are tightened to 165lb-ft. A quick look at your vehicle’s manual should give you this information. If not refer to this handy wheel torque chart online.
Remember, you are tightening the lug nuts to keep the tire in place. You do not have to over-tighten or over-torque the lug nuts to the point that makes them difficult to remove. If you are unsure about your impact driver, you can use the device to get the lug nut close to the surface, then tighten them using a standard lug or torque wrench.
What Happens if You Over Torque Lug Nuts?
Then you may be in trouble. While the bolts that the lug nuts tighten is designed with a little give, over-torquing them may cause the bolts to do one or more of the following;
- Break Off
If any of these things happen to the bolt, then you can damage the wheel itself and other components that are located next to the bolt. This means that in addition to the damage to the bolt, you might be facing damage to the wheel hub itself, causing the threads to be stripped out, damage to the seating surface of the alloy wheels, and perhaps warping the brake rotors, causing the vehicle to grab, pulse, or overheat when applying the brakes.
Over-torquing can be an expensive issue depending on how much damage is done. Which is why you need to learn the right way to tighten and remove lug nuts to minimize the chances of damaging the bolts.
The Right Method to Remove Lug Nuts
The right method takes more than just the right tools, the vehicle itself has to be in the right position and ready for the lug nuts to be removed.
- Park the vehicle on a level surface
- Apply the parking brake
This locks your vehicle in place and helps ensure that it does not roll when removing the lug nuts. If you are changing a tire, go ahead and remove the spare tire from the vehicle and have it ready to go once the tire has been removed.
- Remove the hubcap
- Examine the lug nuts
You’ll want to look for any rust or if they are frozen. A can of WD-40 may be helpful in loosening lug nuts that are showing signs of rust.
- In case of a frozen lug nut, use an impact wrench to break loose the nut.
- For the nuts torqued correctly, use an impact driver or lug wrench to loosen them.
Remember to not jack up the tire at this point, you still want the lug nuts on the bolts when jacking the vehicle up, but only when use can use your hand to take them off.
When ready, jack up the vehicle, remove the lug nuts that are loosened. Now remove the flat tire, and replace it with a new tire. Once completed, you will want to hand-tighten the lug nuts until they all press against the wheel. Now, lower the tire until you can take away the jack. Once in place, you can use an impact driver put the nuts back quickly. Finally, use a torque wrench to tighten the lug nuts to the right amount of torque.
The above information is for regular guys like you and me.
Lug Nut Sockets: Size, Type and Safety
While you are using any sort of impact power tools on lug nuts, you should consider the following three things.
In April, last year I was on a long drive when a nail penetrated into my car tire. I pulled over and changed the flat tire with the spare tire using the manual wrench. Unfortunately, the spare tire didn’t have enough air inside.
Now I was on a long-distance journey and it wasn’t safe for me to continue driving with the spare tire. So when I reached the nearest township I went to a garage to repair the flat tire. The mechanic pulled his impact wrench out and started loosening the nut. But the moment I heard the loud noise coming from the wheel-nut I knew something was wrong…
The guy used a wrong size socket and almost damaged the lug nut. I was lucky that I stopped him before the damage done was too much.
What is the lug nut size of your car wheel? Find out this information first as there is no fit for all socket for lug nuts. You must use the correct size socket that matches with your vehicle’s lug nut. Once the head of the lug nut is damaged it will be very difficult to remove it.
Common Lug Nut Sizes:
The most common lug nut sizes are 17mm, 19mm, 21mm, 7/8-inch, 13/6-inch, and 3/4-inch.
In case you are unsure about the size or more than one car at home, then you can purchase a lug nut socket set. These sets come with all sockets sizes that are suitable for all the popular vehicles.
Most of the impact sockets for lug nuts are designed for impact wrenches which has a square shaft head. On the other hand, your impact driver comes with a hexagonal socket. This means that you either need to find lug nut socket with hexagonal rear end or get a hexagonal to the square adapter as shown in the image below.
Check your impact driver socket size first. Most of them are designed for ¼-inch hexagonal socket though ½-inch and ¾-inch sockets are not uncommon. Assuming that the impact driver you own has a ¼-inch hexagonal socket, you should buy a ¼-inch hex to ½-inch square adapter.
You might have seen the regular chrome-plated sockets for lug nuts. Do not use it on your impact wrench/impact driver. Your impact gun is capable of exerting very high torque and impact force which the chrome plated sockets cannot withstand. The thin chrome socket may break or shatter and can be very dangerous.
Use the impact-rated sockets instead. These are sockets with thicker walls and specifically hardened and tempered to withstand higher torque force. You can find out more about impact sockets here.
An impact driver is a helpful tool in removing and tightening lug nuts. The newer cordless impact drivers with 1500in-lb (125lb-ft) are incredibly powerful. I have seen people changing their car and truck tires using these little power tool. However, it is a tool with limitations, so be sure you have an impact wrench and manual lug wrench handy.