impact wrench safety.

All too often I see people using a impact wrench tightening down lug nuts. This is a very easy way to break or at least weaken your wheel studs. You should ALWAYS use a torque wrench. You can even break them by hand. The FSM for my Tacoma specifies 85ft lbs on lugs. It is possible to turn them a lot more than that but the Toyota gods say 85. As a rule of thumb I only use my impact wrench to loosen stubborn nuts and bolts. You can use it to turn things up until it stops free spinning, when it makes its first "impact" it means its time to get out the torque wrench. It seems humorous to me that the gods have torque specs for everything, but they do. I have a fairly inexpensive torque wrench ($90) they are not cheap and you get what you pay for. I got the half inch drive so I can always step down. There are three types, dial indicator (used for precise measurement, I use them on submarines, we don't want anything breaking down there.), mechanical indicator (dumbed down not very accurate) and snap type(set the desired torque and turn til it snaps) this is the type I have. So do yourself and your truck a favor and invest in one! Also, no lateral extensions allowed (cheater bars, pipes) you can only extend straight down from the drive portion without using one of these equations to correct your torque.
http://www.motorcraftservice.com/renderers/torquewrench/wrench_formula_main_en.asp
Good luck and happy wrenching!

 

Great info!

 

You can also use a *Torque Stick* with your impact gun to tighten lugs.

A torque stick will never be accurate, like a torque wrench..... it can allow you to get 'close' to the recommended torque value and still use your impact gun.

I always torque my lugs on all vehicles @ 100ft lbs. I have a 100ft lb torque stick that I use on the impact gun when tightening. When I'm all done...and the vehicle is on the ground, I'll go over the lug nuts with a torque wrench set to 100ft lbs.

Torque sticks come in a variety of values...and can be purchased in sets.

I only own 1 of them....

 

I took my wife's daily driver prius to have the oil changed and tires rotated. They over-tightened the lug nuts so bad that on several the threads were stretched. I found this out when I decided to do the oil changes and tire rotations myself - it took a hell of a lot of effort with a breaker bar to loosen them. In fact, one broke and had to take it to a shop to get the damn thing replaced. They ended up replacing several due to stretched threads. That was some shit - and they were supposedly as well-known shop...

I always use a torque wrench on my Tacoma and our Tahoe. This won't ever happen again!

 

Up in Canada , tire shops are mandated to use a torque wrench during wheel install .
Just had winter tires installed and they want me back there in a week for a re-torque .

 

Snug them with the impact, torque them with the torque wrench. Especially important on aluminum wheels. If one nut is tighter than the rest, they will all work loose.

 

Good advice there. Several threads have discussed this. However your information on a "cheater pipe" is not 100%. You do not affect the torque applied to a bolt/nut if the cheater pipe is installed on the shaft of the torque wrench where you grip it. This has been discussed and brought up with snap-on tools, and they have verified this. Where you DO affect torque is if you add anything to the socket end of the torque wrench that changes the distance between the socket mounting location, and the bolt itself. THEN you have to make the appropriate calculations. Using a cheater pipe to help you apply force on the handle end doesn't change anything. All that does is reduces the required amount of input from the user. This is of course proven when you think about it, a really strong man can apply more force to the handle than a weaker man. You STILL have to pull enough on the handle to reach the correct setting on the torque wrench. Of course Snap-on does say NOT to use a cheater pipe, but their indicated reasoning for this is to protect the operator from injury if the pipe slips. Pretty much all tool companies have rules regarding alteration to the use.

I do agree that a torque wrench is the proper tool for lug nuts. It is very easy to over-torque. I do use the torque sticks as previously mentioned, and have never had an issue with over tightened or broken lugs.

 

No shit there I was... Put my wheels back on with my impact gun after installing new UCA's/Coil overs and, even though I used my torque wrench to tighten up the new components, I impact gunned my lugs on. Fast Forward 1 week and a trip from NC to MD and back and I have 4 studs break today driving on base. DUMB DUMB DUMB!!!

 

My impact wrench has a torque adjuster knob next to the intlet. you can also adjust the PSI's at your compressor with the limiter, mine is at 90psi. is more than enough for most of all my applications. We have gone thru 14 vehicles my wife and I combined, and have always use impact wrench for tire lugs. I have never had a tire flew out on the highway or any broken lugs.

 

Just because it hasn't happened to you doesn't make it safe.

Impacts aren't recommended for lug nuts because they are more likely to severely over tighten... Saving that little bit of time could be far more expensive/time consuming than just using the correct tool.