How Does the Craftsman Torque Wrench Work?

A Craftsman-made torque wrench aids in tightening bolts in hard-to-reach areas.

A certain amount of torque is pre-applied by auto manufacturers so that critical bolted-on components of the vehicle won't snap if the incorrect amount of torque force is applied. As its name implies, a torque wrench is specifically created for the loosening and tightening of these bolts. One manufacturer of torque wrenches is Craftsman, a brand synonymous with Sears and Sears-related merchants. Properly using the correct Craftsman torque wrench ensures you won't damage the wrench or the vehicle.

Part of the Torque Wrench

Like nearly all modern torque wrenches, Craftsman uses a very similar design to that of wrenches offered by rival companies. By laying out the wrench flat on a table, closer inspection reveals the head of the wrench is comprised of two separate pieces: the arm pin and the retaining ring. They're responsible for being able to handle the actual torque of the project. Other essential parts include grip assembly on the wrench's shaft, the adjustment screw that fine tunes the needed amount of torque and the handle nuts. The torque spring, which counteracts applied pressure, lies inside the shaft itself.

How it Works

By placing the torque wrench correctly over a bolt and turning, the grip assembly turns and goes up a notch to reveal the amount of torque being applied, evidenced by the number gauge on the barrel of the shaft. The adjustment screw automatically pins down the internal torque spring and compresses it to correspond to the torque reading on the number gauge. It also prohibits the spring from returning to a relaxed or noncompressed form, which creates the wrench's audible "tick" sound. By forcing the spring down, counteracting torque-force is applied, which allows the wrench to do its job. When applying torque, small pins inside the assembly automatically loosen and then find the correct torque slot -- the degree to which you're turning the wrench.

Doing the Job

It's a fairly intuitive process: You place the wrench's flexing head around the bolt that needs tightening and make small, incremental turns clockwise. You'll then hear the ticking noises as the pins inside the wrench find their torque slots. Once they do, every time the wrench is turned, the amount of torque is applied and the bolt turns. Once the bolt is tightened, the wrench "relaxes," preventing you from over-tightening and potentially damaging the bolt.

Troubleshooting

Sometimes things can go wonky with the wrench's turning mechanism. Depending on the warranty on your particular Craftsman, if the wrench isn't clicking and the pins aren't locking into place or some other malfunction is occurring, return the wrench to Sears for maintenance. If your wrench is out of any servicing period, perform do-it-yourself maintenance using a small Allen wrench to open the grip and inspect the components. Replacing worn springs is a relatively simple DIY maintenance issue, but damaged pins generally mean that the wrench needs to be replaced.

References

• "Auto Repair for Dummies"; Deanna Sclar; 2007