by Pat Goss
Ahhh yes. I’m sure you’ve all seen that. A technician putting the wheels back on your car using an air impact wrench. Well that is not the right way to do it. You see, these air impact wrenches have grown in power over the years. Back in the day, many many years ago, if they produced 150 ft-lbs, it was a powerful wrench. Well today, some of these are 12 or 13 hundred ft-lbs, and the average is eight to nine hundred ft-lbs of torque. And when you look at that, and realize that the average torque required on a lug nut, to hold the wheel on, is 80 to 90 ft-lbs, well you can imagine how over-tightened some of these lug nuts are. Now that’s a problem because it almost guarantees warped brake rotors. Not only that, but suppose you have a flat tire, and you’ve got one that’s tightened down to five or six hundred ft-lbs of torque. Well the tools that are in the car, or the tools that you might have even put in the car are not going to be capable of loosening those lug nuts. So you’re stranded because you can’t get the wheel off with the flat tire on it.
Now, what’s the proper way? The proper way is to use a torque wrench. Torque wrenches limit what torque goes on to the bolts. How tight they are. They should be used on just about everything , on every repair. Now a lot of people thought that when these electric impact wrenches came out, that that was going to be the answer. Well, it was for a while. Now, these are up to over 400 ft-lbs of torque in some cases. So that’s four times the amount of torque that is needed for the wheels, and most other things on an automobile. Again, back to the torque wrench.
Now, ACDelco has reversed this trend to more powerful and more powerful tools…this is an air ratchet. And its claim to fame is that it’s limited to 65 ft-lbs of torque. So that means that when you’re taking something loose, if it binds up, it doesn’t break the bolt like a two or three hundred ft-lbs torque ratchet would do. So it helps make you a better technician. So remember that most everything on an automobile has a specified amount of torque. And the biggest and best friend that you can have, if you’re going to do any work on your car, is a torque wrench.
And if you have a question or comment, drop me a line, right here at MotorWeek.