How to choose springs and what are they?

Springsused for a very long time, long before the invention of cars. They are made of steel and look like arches, supporting the weight of the car and holding the axle in place.

Automakers seeking to improve the ride quality of light passenger cars have developed mono-leaf springs. Because these springs are thickest in the center and thinnest at the ends, variable stiffness (like springs) is created and they support the weight of the car and hold the axle in place. As a result, the use of such springs improves the ride quality of small cars and provides a soft ride, helping to control the car in sharp turns.

Currently, there are two most popular types of springs:single-leaf and multi-leaf. The first are used for small cars, and multi-leaf - for larger vehicles.But what is the difference between them and what other springs can there be?

In this article you will learn:

• How is the spring suspension arranged?
• Advantages of springs in the suspension
• Disadvantages of spring suspension
• What are the types of springs?
• How to determine spring wear?
• How to maintain the springs?

How is the spring suspension arranged?

The central steel sheets are responsible for attaching the suspension to the axle of the car, and the ends of the sheets are connected to the frame of the car with the help of hinges or earrings.

Some suspension systems have only one metal sheet, not several, such systems were used in the middle of the last century in the USA. These systems were installed on cars of the brandFord, and in just a few years this system became popular among European automakers.

When meeting an obstacle, the spring sheets bend a little, dampening all vibrations that occurred as a result of the collision. If there are several sheets, then a large load falls on the lower spring, so it is made shorter, achieving the smallest bend. The upper springs, on the contrary, are made longer in order to achieve greater flexibility and dampen the vibrations left after the lower sheets.

Today, springs are used inpickups, SUVs and large trucks. They are installed in front, behind, along the frame beams or transversely on differentsuspension types.

Advantages of springs in the suspension:

• simple and have fewer moving parts that can wear out;
• keep the rear axle in place, so there is no need for complex suspension mechanisms;
• with a large weight, they distribute the load on the chassis of the car more evenly compared to springs or torsion beams.
• the friction between the multiple sheets as they slide helps dampen the natural up-and-down rebound effect of the springs, making the ride more stable and reducing stress onshock absorbers.

Disadvantages of spring suspension:

• when the leaf springs are attached directly to the rear axle, the torque generated during hard acceleration or braking can cause the axle to spin. This results in vibration and considerable squatting of the rear of the vehicle. This mount also requires stiffer springs, which reduces the level of ride comfort that softer springs could provide.springs.
• this design provides very little adjustability and is not suitable for suspension tuning, because adjustment is possible only by changing the number of sheets in the spring package or changing the material composition in order to change the characteristics of strength and flexibility. For example, the Chevrolet Corvette T56 (5th generation) uses fiber-reinforced plastic springs.

What are the types of springs?

1. Many-leafed
2. Monolistova
3. Semi-elliptical
4. Quarter elliptical
5. Three-quarter elliptic
6. Fully elliptical
7. Transverse

By number of letters:

• Multi-leaf spring

The most common type is the multi-leaf spring, which consists of more than one metal plate or leaf. These plates are stacked on top of each other, with the longest part on top. A center bolt is inserted through the thickest part to hold the plates together. Standard components have from three to five flaps, but can be found with more.

Multiple leaves increase spring stiffness. Additional support leads to an increase in load capacity, so such springs are suitable for cars with a large load capacity. But be careful when using springs with too much leaf, as this can lead to over-stiffness and an uncomfortable ride.

• Monoleaf spring

Another type is a mono-leaf spring, made from a single sheet of metal. They have a thick center section and taper to the edges to provide support, just like leaf springs. They are used mostly on light cars.

According to the shape of the leaf spring:

• Semi-elliptical spring

This is the most common type listed here. It consists of several sheets of the same width of different lengths, including the top and longest sheet, which is called the "main sheet". They are attached to the car frame and brackets. Semi-elliptic springs are installed on the front and rear axles of many vehicles, mainly on the rear axle of passenger cars. They are affordable, last a long time and do not require frequent repairs.

• Quarter elliptical spring

This type is similar in design to a semi-elliptic spring, but they are used mostly on older cars. The distinguishing feature of this suspension component is that it is only half of a semi-elliptic spring. One end is attached to the side of the frame with a bolt, and the other end is connected to the front axle. This type of spring is also called cantilever.

• Three-quarter elliptical spring

If you combine a semi-elliptic spring and a quarter-elliptic spring, you get a three-quarter elliptical spring. The quarter-elliptical part is located on top of the axle and is attached to the car frame. The semi-elliptic spring is connected to the frame through a bracket on one side, and the other end is attached to the quarter-elliptic spring.

Adding an extra half of this suspension component provides extra support. A three-quarter elliptic spring is popular on older cars.

• Fully elliptical spring

It is a combination of two semi-elliptical springs that connect opposite each other, creating a shape similar to an oval. They are attached to the frame of the car and to the axle. Since both springs flex equally during compression, spring brackets are not used.

Full-elliptic springs are mainly used in older cars. Nowadays, they are rare because they do not ensure proper axis alignment.

• Transverse spring

This type of spring is very similar to a semi-elliptic spring. The only difference is that it is upside down, so the longest leaf is at the bottom. It is attached to each wheel, not above them. The middle or thickest part is attached via a U-bolt. They are also mainly used in older cars, often in independent suspensions.

How to determine spring wear?

When worn, springslose their elasticity and begin to sag. As a result, the height of the car decreases. If you suspect that the spring is worn, it is recommended to measure the height yourself and compare it with the manufacturer's specifications. Lower ride height and loss of spring rebound can lead to complications such as the car sinking over bumps, which is harmful to suspension components and the entire car in general.

In addition to the above, springscan develop cracks and corrosion over time. When the rubber bushings in the spring lugs and brackets dry out, the ride can become stiffer. You can choose fasteners for springsat this link.

How to maintain the springs?

When a driver has just bought springs and installed them, the last thing he wants to think about is repair and maintenance. But it is better not to be lazy with the last point and not to ignore the need to periodically check the condition of the springs on the car.

These simple actions will help to significantly increase the life of the suspension:

1. Monitor the condition of the bushings, installed on the front mounting of the springs. Their declared resource is 50,000 km, but it may change to a lesser extent depending on the terrain, driving style and other factors;
2. Periodically check the condition of bolts and nuts. From vibration, the strongest connections are gradually loosened and untwisted. Before leaving, evaluate how the bolts are tightened, tighten them for warranty. It is usually recommended to do this every 7,000 to 10,000 kilometers;
3. In the rear lug, where the spring is in a floating position,it is important to change the oil regularly. Dust, pollution, water spoil it, so it is necessary to periodically add new lubricant. To add it, you need to bend the spring plate with a powerful crowbar or mount and grease the space that opens up.But be careful not to hurt yourself, especially your fingers.
4. Can be used as lubricants: solidol, lithol, graphite grease, etc.