I had a flat tire on my truck over the weekend. I tried to pull it off with my electric impact gun, but it wasn't turning the lug nuts at all. Apparently, the last joker to do anything on the tires ran them on with an air gun and no regard for proper torque. This meant I needed to apply more torque than my power tool could provide.
Torque is a measure of rotational force, commonly expressed in foot-pounds. One pound of force, applied at the end of a 1 foot lever, is one foot-pound. To increase the amount of torque applied, you either add more force or a longer lever. There is no practical way for me to increase the torque output on my impact gun, so I had to use a manual method of turning the lug nuts. Increasing applied torque with manual leverage is very simple: add more feet or add more pounds.
I weigh in at right about 190 pounds, depending on what's in my pockets, which means I can apply about 150 pounds of force, give or take. (I have to stay on my feet, so a significant chunk of my mass is lost to that.) On a one foot lever, that means I apply somewhere in the neighborhood of 150 foot pounds of torque; if I have another person pull on the lever with me, we can apply double or more the amount of force I can apply alone. It works, but it's clumsy and cumbersome and sometimes you don't have another person. The easier way is to add more feet to the lever. This is commonly accomplished using an item called a cheater bar.
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| My cheater (L) and breaker (R) bars: the best nut-busting combo a guy could want. |
In short, a cheater bar is anything that extends a lever. Most of the time it's a pipe of some sort slipped over the end of a socket wrench. My personal favorite cheater is a four foot floor jack handle; it will fit over the handle of any ratchet or breaker bar that I own and adds about as much length as I can reasonably use. With a 5 foot lever I'm applying roughly 750 foot pounds of torque, and if that won't break something loose, not much else in my world will.
Archimedes was right: with enough leverage, you can move the world.Lokidude
That's why I have a 32" 1/2 Drive breaker bar with my
ReplyDeletejacks
The very first thing I do when I get my vehicle home after wheel work of any kind is break and hand torque all lug nuts. Garage monkeys only know how to put them on improperly using an impact wrench. I think they like to pretend their in the pits of NASCAR.
ReplyDeleteI bought a torque multiplier for just those cases, but so far it's been unused.
ReplyDeleteAnother trick is to position the end of the breaker bar so that you can use a jack to lift the breaker bar.
When that fails, and the wheel and vehicle lifted, I jumped up and down in the bed over the frozen nut, and it lugnut came free.
And yes, I carry a long breaker bar and a six point deepwell impact socket in each vehicle.
Good post.
I have used all of these tips in the past to break free a nut put on by some grease monkey that didn't use a proper torque wrench for correct tightening. One problem I had, many, many years ago, was a flat tire, with one of those over torqued lug nuts.
ReplyDeleteI had a socket set with a breaker bar, plus a short length of pipe, so it was no problem putting extra torque on it to get it loose. The problem was, somehow, I pulled the wheel lug through the hub, and it would thus only spin, without allowing the nut to come off the bolt of the darn lug. I had to get a tow and have it torched off and had all the lugs replaced, to be sure they were good.
Pigpen51. Murphy always has the last word.
DeleteI watched a video by a very good mechanic and he shows drilling our the center of a frozen or messed up lug nut until you can snap it off.
https://www.youtube.com/watch?v=0Oi_DU-r5Wc
But it isn't something you can do by the side of the roadway.
Our state requires the inspection station to remove two wheels and look at the brakes.
They always return somewhat over tightened.