Whenever the vehicle sags to one side or in the back then it might be a sign that there is need to re-arch your car’s leaf spring. This type of sagging affects the appearance of the car and can also interfere with handling, steering, and braking. It can be difficult to undertake this process on your own, however with the right tools, it becomes possible.
The leaf springs will equally need rebuilding after being re-arched. This involves replacing all the parts, as it is not encouraged to re-use any of the old components. Ensure that the new parts are an exact match for the type of vehicle being repaired.
HOW TO RE-ARCH
There are two ways used to re-arch leaf springs. The most regular is cold pressing which uses a special press to change the arch. This gives a short term solution to the problem as the steel leaf springs have a memory which easily gets them to the height they were before being raised. As such, it is highly advisable not to re-arch using cold setting.
Heat treating however involves erasing the spring’s memory by annealing and then re-shaping. Heat treatment is applied on each leaf in turn before they are reassembled and re-installed.
COLD ARCHING METHOD
This process uses special machine. The spring is first clamped in a hydraulic clamp to dissemble its parts. Then, each leaf is placed across arbors and a hydraulic press pushes it down between the blocks. Pressure is fully put across each leaf at a 90-degree angle to its length. This is done from one end to the other, thus moving across different points on its surface. Pressure is then applied until the entire length of the leaf is covered, and a rhythm is developed to be sure of even application of pressure, as applying too much in any one area can easily break a leaf. This process re-arches each leaf individually.
To complete re-arching using this process, spring leafs are re-assembled in their original position while the mechanic tries to get the same orientation using new center bolts and tie clamps.
The material used to manufacture spring steel has a memory that makes it return to its shape. In this process, the spring is first taken apart and a technician inspects it for damage or wear and tear. Then, rust, corrosion, paint, and any other kind of finishing is taken from the surface by blasting, and they are re-inspected. If they are still in good order, each leaf is heated to at least 1650 degrees Fahrenheit to be re-shaped. While still malleable, the spring is shaped using the correct shape and arch before being placed in a special oil to cool. The spring is then re-heated to at least 950 degrees Fahrenheit to put it to the correct hardness.
RE-INSTALL THE LEAF SPRING
After the reforming of the leaf springs, the final product is well-tempered, arched, and shaped. Then, they can be re-installed in their proper areas.