Cars and trucks are made up of thousands of different parts, components, bolts, washers and bushings. When the engineers design them, they have certain torque values that the bolts should be set to that will ensure that they are tightened properly so they do not come off, and also so that they are not over-tightened and weakened. Every bolt has a specific assigned torque value, so the bolts that hold on components like the sway bars need to be tightened to those values.
A sway bar on a car or a truck is a cylindrical length of metal that goes from one side of a vehicle's suspension to the other and is bolted in place. Most vehicles use only a front sway bar, while some use front and rear sway bars. The purpose of a sway bar is to reduce the amount of body roll, or lean, that a vehicle experiences when driving around a corner. As the vehicle goes around the corner, the bar acts as a lever, forcing the side of the vehicle that is on the inside of the turn towards the ground. This reduces body roll and results in more stability and better grip in the corner, since the tires have better contact with the road and the weight transfer of the vehicle is better controlled.
A sway bar is a relatively simply device that consists of a few different components. The bar itself is a tubular shaped length of metal that goes from one side of the car to the other and that is bent in such a way to clear any components on the car it is located near. Near the middle, the bar is bolted to the chassis with brackets. There is a bushing inside the bracket that the bar goes through and that isolates the bar from direct contact with the chassis. At either end the bar is fastened to the suspension with end links that come off the bar at 90 degrees. The end links either slide onto the bar or are bolted to the bar.
Like every bolt on a vehicle, the engineers have determined what the sway bar torque settings should be. Torque settings vary widely depending on the make and model in question, so there is no universal torque setting for sway bar hardware. The best way to determine what the proper torque settings are on a sway bar is to consult a workshop manual that has the torque settings for the make and model in question. Depending on the vehicle, the torque setting for sway bars can be as low as 30 or 40 foot-pounds, or it may be higher.
Once you have determined what the proper torque settings are, use a torque wrench to tighten and check the bolts. Place the proper socket on the end of the torque wrench. Place the socket onto the sway bar bolt and tighten the bolt, reading the setting on the torque wrench as you tighten the bolt. Stop tightening the bolts once you have reached the proper torque setting.
