Leaf spring for your car

Proven and robust: The leaf spring The leaf spring is one of the oldest principles of damping a suspension. It has its origins in the field of carriage construction and offered a significant increase in travel comfort long before the invention of the air tire. The leaf spring decouples the cabin of a vehicle from the bumps in the road. To this day, its simple principle, low-cost manufacturing and high robustness make this type of spring system a default component in heavy vehicles. Functioning of leaf springs Unlike a coil spring, this with this spring principle achieves its damping effect via a package of leaves. The leaves are stored on top of each other in a gliding manner and linked with clips. During compression, the leaves bend and slide past each other. The resulting friction contributes to the spring effect, but is reduced to a minimum by grease or oil. In carriage construction, two leaf springs were mounted one above the other. The result was an elliptical spring. Today, the semi-elliptical spring is the most common form of this type of spring. Other variants of this component include the spring links, parabolic springs and transverse leaf springs. Application areas of leaf springs The advantage of this spring principle is that large loads can be precisely damped with limited means. This makes the leaf springs an inexpensive component of the suspension in heavy vehicles. Therefore, trucks and rail vehicles are by default still equipped with a leaf spring suspension to this day. This type of spring is also still popular on the rear axle of SUVs and vans. It is less suitable for front axles, because the leaf springs require a lot of space. Due to the low cost and hardly complex construction, use of leaf springs is also very popular in trailers. Leaf spring defects Leaf springs may break as a result of corrosion or overload. If the grease lubrication between the leaf layers is lost, the leaf spring starts to squeak vociferously. Abrasion damage will then quickly occur, destroying the leaf springs from the inside out. A broken spring immediately renders the vehicle immobile, leaving no other option but towing it. The springs should be checked twice a year. Repairing leaf springs Leaf springs can be repaired using the appropriate tools. The individual components can be purchased. Whether this makes sense depends on various factors. When self-constructing leaf springs, one may also employ inserts made of plastic, graphite or carbon instead of grease. These prevent mutual seizing up and for the most part keep the leaf springs maintenance-free. When a leaf spring needs to be lubricated and greased, a subsequent taping is sensible. Currently, there is only one manufacturer offering special "fat tape" for taping of leaf springs. A role costs about 8 euros and promises good results. The same manufacturer also offers a special corrosion protection grease, which can significantly extend the life of intact leaf springs. Replacing leaf springs If the leaf springs are displaying clear signs of wear, such as corrosion, cracks or seizure marks, the leaf spring should be replaced. The simplistic construction principle makes this spring inexpensive. A new pair of springs must be estimated between 50 and 200 euro. Their replacement is quite simple: The vehicle is jacked up so that the wheels hang in the air completely freely. A retractable arm is used to lift the rear axle until the leaf springs are relaxed. They are usually simply bolted to the body and to the axle with a U-shaped bracket. Once these connections are loosened, the leaf spring can be removed. The new leaf spring are mounted in reverse order. Using the appropriate tools, a leaf spring can be replaced in just a few minutes. All fittings and brackets are typically included with a repair and exchange set. If not, these should always be purchased to ensure a maximum level of safety. It also saves a lot of work during the dismantling: If the old leaf springs cannot be removed using conventional means, they can simply be cut off using an angle grinder.