Beware of lubed wheel studs / use of impact gun

I've been lubing lug threads for years. I guess I've learned something today. Thank you.

 

My tire change tools are electric impact for removal, speed wrench for initial snugging up and a small flex bar similar in length to the bar in the on board tool kit. That way I can still change a tire roadside if I get a flat. (Otherwise I won’t be able to break the nut free). There is no way I can break a wheel stud lubed or not with my bar unless it has already yielded.

I see it all the time with our apprentices. They love their cordless electric impacts. Give a guy with limited experience a 3/4 electric impact and wonder why things either break or I need my 40” breaker bar with a piece of tube on the end just to break it free. I just bought a Milwaukee 1/2” mid-torque cordless impact. 600ftlbs removal, 450ftlbs fastening. Now if I went with the Milwaukee high torque it is essentially the 3/4 with a 1/2” output drive. 1100 ftlbs removal and 700 ftlbs fastening. If what I have found online is credible the correct torque is 83ftlbs. Do you really think you won’t over torque the lug nuts with “low powered” electric or cordless impact?

Now as far as torque limiting extensions I still hate them. I don’t trust them. I teach my apprentices to hand tighten or torque wrench. If I didn’t hand tighten today I never would have felt it yielding.

 

Yep. 83ft-lbs.

One or two ugga-duggas with my electric impact after my finger is already off the trigger still allows the socket to turn at least a quarter turn before I get a click. Just me at home doing my thing.

 

three ugga duggas and I don't even need to take a torque wrench to them

 

80 ugga duggas equals 80 foot pounds, right? Thats what I use anyway

 

oh... oh my god your right

 

You guys are mixing up your metric and SAE Ugga Duggas.

 

I broke a damn stud using a very low powered impact...not a big deal. You can buy a replacement for a couple bucks and change it out in 15 minutes.

 

Torque sticks are a different beast, I don't immediately cringe when I see a tire monkey using them just as long as they don't sit there hitting it forever. Not sure I absolutely trust them or not, though.

 

https://www.urbandictionary.com/define.php?term=ugga dugga

 

The “ugga-dugga” method? Sorry I didn’t realize your skill level and tool set.

 

Guys, this post is not directed at Tony but at everyone who trusts torque sticks, tables comparing dry versus lube and everything else. Be careful is the key here. Below is an article I wrote a few years ago discussing this topic but first, let me clear up a few wrong ideas In some of these posts:
Just because the studs are designed to break if overtorqued does not make them shit. It means they were properly designed and specc'd. Also yield is not the same as stretch. Anyhow, here is what happens between dry and wet torque (this includes water too) and why you should only use a torque wrench on dry, clean studs. Enjoy!

Torque, when dealing with bolts and nuts, is a very simple formula that can get complicated real fast. T = K × D × F where T = torque, K = nut factor, sometimes called the friction factor, D = bolt diameter, and F = bolt tension generated during tightening. This formula is often called the short-form equation and you don't really want to see the long form expression. Let me explain a few parts of this equation and the parts you folks are discussing: T= Torque, which is sort of a way of measuring "clamp force" when dealing with your wheel studs. Other ways are used but I will leave those alone. K= Nut or Friction factor....or in my world the CYA or fudge factor. Very important multiplier that can change for different applications and usually only determined by actual testing. In the situation you described it gets complicated. Here are some of the variables that could change the "K" factor in the equation: Is the bolt plated? Is the plating zinc? Is the bolt lubricated? If so, what type? What is the bolt's temperature? Has the bolt been pre loaded before? If so how many times and was the preload correct? And on... D= Bolt Diameter F= Bolt tension. The bolt tension is caused tightening. The bolt is stretched a bit during tightening. In some cases the thread can be deformed which you guys know as "stripping". Bottom line: Can lug nut torque be changed by lubrication? You bet. How much? I have not a clue, sorry. Some people have tables that states a percentage and while that may be true in some applications I don't know if it applies here because: A) Even though you have multiple lug nuts they act as one unit. The K factor will change depending on if all bolts are lubricated or only one, or two, etc. B) Type of lubricant makes a huge difference. Don't say "It was oil" 'cause that won't help haha. C) What was the temperature? Makes a big difference too. D) How many times have they been torqued and were they torqued properly before? All in all, it is a good idea to clean your bolt before torquing unless it was designed to be lubricated, which wheel studs are not. So yes, lubricating a wheel stud before torquing the lug nut could cause the stud to break because your torque values will be higher. Just don't know by how much. Hope this helps and tried to keep it simple.

 

The ugga dugga method is tried and true. Just gotta have the touch.

 

I respect you as a designer and fabricator. Please don’t tarnish your reputation as a skilled tradesperson.

 

You wouldn’t like hanging out with me then. I own a lot of tools and every one of them has been used as a hammer at least a few times. Especially the batteries for my power tools. Lot of my tools have been used at chisels and pry bars too.

For real though, we are talking about a truck wheel here. Not assembling the space shuttle. Make the lug nuts tight and don’t cross thread them. Don’t go hulk on them. Or, you know, 4 ugga duggas on setting 3 with my Dewalt impact gun.

 

Conversion formula? Preferably the one with non-lubed factoring...

 

Time is money and every tech I've ever worked with uses impacts. Experience when using torque sticks and your impact results in close to spec torque values. If i buy a new impact I get a feel for how it performs and follow up with a torque wrench to make sure I'm dialed in.

If a tech decided to only tighten wheels by hand he wouldn't be working in the trade for very long.

 

Apparently he’s only guilty of being a terrible comedian.

Or you, a terrible audience.

 

Yea. I had a guy tell me a should get the “right” tool for the job. I told him to buy it for me and then go get it out of my toolbox every time I’m laying under the truck and need it. The right tool for the job is the closest one that gets the job done.

 

There are proper tools for each job. If you need a faster tool get an air ratchet. Offers the speed of an impact yet the control of hand tools. Unfortunately many see tools as an expense and would rather buy a case of beer instead. Since they already have an impact why spend good beer money on the right tool for the job.