OT: Impact wrench vs. breaker bar

Question: will an impact wrench remove fasteners without destroying them that a breaker bar cannot?

Here’s the background. 2005 Explorer went in to the dealer last summer for some exhaust work, dealer said all four struts needed to be replaced, I said OK. Dealer said he could not replace RR strut, as they could not get wheel off. Said they tried breaker bar with pipe extension, no luck. I found that a bit tough to take, as car had had tires replaced six months previously. Why they didn’t use impact gun to loosen I don’t know.

Next time car was in, I asked them to please make sure all lug nuts could be removed. Obviously, the last thing I wanted was to be stuck on the road in the middle of nowhere with a flat and no way to change it. They said they had loosened and re-tightened all lug nuts, and all were fine.

Month later, I wanted to check the emergency brake shoes. RR lug nuts again a problem. Too tight to loosen with a large four-way wrench. Tried a breaker bar with a pipe on it, but worried it would bend. So I went down to HF, bought their heaviest breaker bar - 36”, 3/4” drive. Had to turn down a six-point impact socket to fit into the wheel. Got the wheel off, but broke two studs in the process. Went back to the dealer. They were embarrassed and replaced the studs, no charge.

When I got the car back, I loosened and tightened all of the lug nuts just to be sure. I put Never-Seez on them. Yeah, I know they don’t recommend it, but I don’t mind checking them periodically.

Which all made me wonder - if I had used an impact gun rather than the breaker bar to remove the frozen lug nuts, would those studs likely have snapped?

Usually with a breaker bar you can feel what's going on, like if the nut is rounding or the stud is twisting rather than the nut coming loose. With an impact gun you really don't get that...all you get is snap. Although an impact gun is easier to do tightening and loosening cycles to try to break a fastener loose.

The problem is using an impact to put the lug nuts on that's set way too heavy. Tire shops are always behind with people waiting and I don't think they bother checking what the impact is set at. It's probably ok if you don't dwell too long on any one nut. Impacting too long will give the same result. Yeah if they were on that tight an impact would either loosen them of shear the bolt, probably the latter.

I think an impact gun is great if you set the torque at less than breaking torque.

likely few people do that. I will have to ask my son Matt. he went to a high-class mechanic school(UTI).

Re: UTI: Your New Career Path Starts at Universal Technical Institute

With his bonus added he makes about $60. per, and great bennies so that talent worked out for him.

The short answer is... Maybe.

There are a lot of variables. An impact wrench does just that, impacting torque applied in direct alignment to that axis.
A breaker bar however can easily apply the load in two or more directions. I've seen many snapped lug studs and rounded lug nuts from breaker bar/ tire iron use or misuse even when using the correct socket.

Over torque occurs by both owners and shops, but can also happen on account of corrosion between the aluminum wheel and the iron hub. I've seen hundreds of vehicles lug studs snapped off by this alone. Using some form of correction preventative on the hub surface and between the lug nuts and wheel will aid in roadside repairability.

( By the way dad and I use grease on all of our vehicles lugs and hubs and have never had a problem caused by it with several million miles of combined use. ) Just get them lugs correctly torqued the first time.

Lubrication is often required for precision torquing critical components.

Impact guns do not have torque settings as in foot pounds, just 1.2.3 positions.
Proper torquing is supposed to be accomplished by torque bars or torque sockets specifically designed for impact guns.

Personally I have no scientific proof to support my idea but my instinct says impact wrench less likely to break studs.
Try drilling a body hole in a piece of stock that will fit into the wheel counter bore and smack the living sh*t out of the nut. Lots of times this will free up a nut. Bolts too.

I've been on the side of the road at night with stuck lug nuts. Many bad words later and somehow finding a cheater bar I got them off.

Unfortunately lots of tire guys get little to no training. They are told, or think, tight is better. And never, ever, use any lubricant. Tightening a dry fastener as tight as you can into an alloy wheel is a bad deal.

In the mid-1960's, There was a new thing called studded snow tires. I had my local gas station/car repair shop sell me a set and install them. Somewhere in the annual snow tire/regular tire R&R cycle that followed, The kid with the impact wrench admitted that two wheel studs had "just snapped off" while he was changing the tires. It seems he had not been instructed to turn down the air pressure for that job. I had to drive home with one wheel held on with three studs, get twenty new studs at the Olds dealer and have the gas station replace all of them. Some more studs broke when all the tires were removed to install the new studs. I decided studded snow tires were too much trouble and stopped using them. After that, I always used a hand torque wrench if I had to mess with wheels on my cars at home. Except the '67 MGB, which used a King Dick hammer to change wheels.

Then came the "torque sticks" that seem to assure that kids with impact wrenches do not over tighten the studs if they use the correct stick.

Larry

If you have an adjustable impact wrench it can often get things loose without breaking.

First, any time something like that is "stuck" the first move should be to apply a good creeping penetrating fluid and let it sit for a while. Then, try loosening with the impact wrench. If after a few seconds it doesn't loosen switch the wrench to tighten on a wheel stud safe setting.

The drill is:

2-3 seconds on loosen, followed by 1-2 seconds on tighten. Repeat as necessary allowing breaks for things to cool. The idea is to "shock" the fastener into even micro movements, which also helps the fluid to penetrate. As things progress the micro movements will get larger and larger until the nut starts to move.

Using that method it once took me 15 minutes to remove a badly stuck bolt holding a fork lift counterweight on. I eventually got it out without breaking anything. A 1" impact wrench might have helped but all I had was a 3/4" one.

For wheel studs and nuts I use white grease such as Lubriplate. It eventually thins to an oil like consistency that stays put through multiple wheel changes. I also use the "3" setting on my IR impact wrench (max is 5) when tightening lug nuts. Tight enough but can be removed with a lug wrench if needed.

For other things I have had success using a breaker bar where the improved feel let me know what was going on.

My brother was rebuilding an old Case backhoe and had one nut or bolt that just wouldn't budge with a impact or breaker bar. He tried a pipe on the breaker bar and that also didn't work so he tried two pipes, one on each side of the T handled breaker bar and a friend on the other end. That finally persuaded it to break loose.

Joe Gwinn said:

I have been greasing wheel lug studs forever, using wheel-bearing grease. Prevents corrosion. What keeps the lug nut from unscrewing itself is the elastic deformation of the the wheel rim steel around the conical hole where the lug nut clamps the rim. The forces are sufficient to squeeze the grease out of the high-pressure contact areas. It's the same kind of mechanism as what keep engine headbolts from loosening - the bolt stretches elastically, maintaining contact pressure despite vibration et al.

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It's when elastic goes plastic that shit gets fun.

About two months ago I had to visit the local Discount Tire store. (Great folks, by the way)

After getting tires I required, I asked them to please use a torque wrench to tighten the lugs.

The guy told me that the corporate policy is to ALWAYS use a torque wrench for the finish operation.

Like I said, great folks, but they ONLY do tires.

For your vehicle 100 ft lbs. is the spec. Not hard to exceed that with an impact.
My SUV says 68 ft lbs. so always check your manual and use a torque wrench.
A tire shop that doesnt use a Torque wrench or a calibrated impact wont get my business.

plastikdreams said:

It's when elastic goes plastic that shit gets fun.

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Yep, which is why if using any kind of lubricant on lug studs one ought to reduce the torque. I use antiseize on lug threads but not on tapered seats. I also drop the torque about 20%. Using lubricant on the lugs without reducing torque might get you a front row seat to a wheel from your vehicle passing you on the highway. And I generally use a 1/2" drive impact on its lowest setting for putting the wheels back on, then final torque with a torque wrench.

Thunderjet said:

About two months ago I had to visit the local Discount Tire store. (Great folks, by the way)

After getting tires I required, I asked them to please use a torque wrench to tighten the lugs.

The guy told me that the corporate policy is to ALWAYS use a torque wrench for the finish operation.

Like I said, great folks, but they ONLY do tires.

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OT but yes - they do a great job with their procedures! They are a great customer of ours and have one of our torque wrenches in every bay in every shop. We make virtually all our own components, so some of the parts in those tools are ones the fine people on PM have helped me troubleshoot and improve the processes of making on!

One of the few ,then......there is an allegedly workable system of using different (coloured) extensions twixt rattle gun and wheel nut..........anyhoo,good example.....mobile tyre fitters truck comes out to service (fix) a flat on the Case 580 backhoe.....one wheel ....and somehow ,they managed to remove both fronts,and when put back with a Yutani* rattle gun......every stud was partially fractured thru the thread root in multiple places .....only 5/8 UNF studs,five of,not much bigger than a car..,..One stud broke first few hours ......when I fronted the manager ,it appears they see all offroad as 22mm studs used on big trucks,and tighten the crap out of it...(Yutani is the rattle gun all the tyre places use)

L Vanice said:

In the mid-1960's, There was a new thing called studded snow tires. I had my local gas station/car repair shop sell me a set and install them. Somewhere in the annual snow tire/regular tire R&R cycle that followed, The kid with the impact wrench admitted that two wheel studs had "just snapped off" while he was changing the tires. It seems he had not been instructed to turn down the air pressure for that job. I had to drive home with one wheel held on with three studs, get twenty new studs at the Olds dealer and have the gas station replace all of them. Some more studs broke when all the tires were removed to install the new studs. I decided studded snow tires were too much trouble and stopped using them. After that, I always used a hand torque wrench if I had to mess with wheels on my cars at home. Except the '67 MGB, which used a King Dick hammer to change wheels.

Then came the "torque sticks" that seem to assure that kids with impact wrenches do not over tighten the studs if they use the correct stick.

Larry

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“ King Dick “, that’s a blast from my past.

Regards Tyrone.

barbter said:

I hope that's got nothing to do with Mancunian nights out drinking....

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No. A workmate of mine never got on with the foreman. On the last day of his notice he went into the foreman’s office and slammed a big “ King Dick “ spanner down on the desk and said “ I think this must be your’s, it’s got your name on it “.

Regards Tyrone.

As far as I know it’s a legal requirement to set lug nuts by torque over here, I haven’t checked that’s what the local tyre centre told me, I watched them setting the nuts with a torque wrench, they did run them on with an impact gun I asked the guy who said it was set to minimum, well below what it should be.
You may need a torque multiplier to shift bad ones, think mines 10:1, I haven’t failed to shift a nut, I saw a section of a stud once that was the wrong steel, it had flowed plastic flow the thread was really wonkey, cheap studs?
Mark