- What is the front suspension of a car, what is its function
- What are the typical malfunctions of the front suspension arm of a car
- How to remove and replace the front suspension arm of a car
It may seem that replacing the front suspension arm is a complex matter and, in order to remove this problem from your shoulders, it is better to contact a car service. But there they will definitely ask you for a tidy sum. Why not try to do it yourself? Before you remove the front suspension arm, you need to generally understand how the suspension works. It is better to familiarize yourself with the instructions in advance and find out what tools and spare parts you may need. But first of all, you should understand what the front suspension is and how it works.
Purpose and main elements of the suspension
Wheel suspension was created much earlier than the car itself. Initially, it was used on horse-drawn carriages, which were intended for a comfortable ride over long distances. At least 4 wheels were installed on them, because of this, the designers had to worry about how to ensure the vertical movement of the wheels relative to the body. This was especially important for riding on rough roads.
The first suspension designs were created during this period. Later, almost without any changes, they were also used in the first machines, which had just begun to appear on the market. The speed of these cars could barely reach 30 km / h. But with the development of the industry, it was necessary to revise the approach to suspension designs.
Initially, the suspension was perceived only as a means of achieving the most comfortable ride, but the cars became faster and the emphasis shifted to the quality of handling. In the 20s of the last century, a new car organization system appeared: an independent suspension system was created for the front, and later for the rear wheels.
There is:
- guide elements that provide a given trajectory of the wheels relative to the body;
- elastic elements responsible for the required force of movement of the wheels;
- elements whose purpose is to damp vibrations.
Guiding elements: levers, racks, ball joints and rubber-metal joints.
Elastic elements: springs, springs, torsion bars and pneumatic chambers.
Top 3 most common car breakdowns:
Almost every day I see how an undetected and uncorrected problem leads to an expensive repair, and even to neglected cases, to accidents (God forbid, of course!).
I believe that it is CRITICAL IMPORTANT for everyone to know about the 3 most common problems that motorists face most often (below you can download a document that details all the possible problems):
1) Dashboard Warning Icons: Engine Check Indicator
The “Engine Check” icon on the dashboard is the most common problem for cars and trucks. This indicator on the tidy lights up when the computer (electronic engine control unit) detects an error code in the system in the operation of any system. In total, there are more than 200 possible error codes, in order to identify the cause, you need to do a full-fledged electronic diagnostics in the car service nearest to you (most often it is free).
2) High fuel consumption
When the engine is operating normally, it burns fuel at a speed that helps to efficiently consume fuel (we get fuel economy). However, some parts of the fuel system, such as fuel filters, air filters, mass air flow sensors and oxygen sensors (lambda probe), become dirty and worn out over time. If they are not replaced (and this is the most common reason for increased fuel consumption), then this will lead to the fact that the engine will consume more fuel than usual.
3) Squeaking brakes
Brakes in a car are sacred. It is from them that the safety of our car, and sometimes life, often depends! Therefore, when you notice any signs of problems, such as a squeal, a creak, or if, for example, the brake pedal becomes soft, you should, of course, show the car mechanic as quickly as possible. Most often, a creak or squeal suggests that it is necessary to replace brake pads or brake discs.
Some car breakdowns are not critical and allow you to operate the car, while others, on the contrary, require immediate intervention.
Elements for damping oscillations: various shock absorbers.
The classification that we cited is relatively arbitrary, because in various types of pendants, some details may well perform several functions at the same time.
For example, a spring. Initially, it was used in carriages. Spring helped to remove the intensity of vibrations due to the mutual friction of its sheets. In addition, sections of springs with an asymmetric shape served as levers.
Due to its functionality, springs have been used everywhere. Such a classification of key elements gives a clear understanding of the dependence of the spring characteristics on the replacement of any of the above parts. For example, the position of the wheels depends on the guide parts, the stiffness of the suspension device is associated with elastic elements, and the damping efficiency is provided by shock absorbers.
The most common designs and front suspension
To date, most small and middle class cars are equipped with McPherson suspension.
In the figure – the device of the front node of this type:
A distinctive feature of such front suspensions is the ability to share the lower arm and telescopic upright. In such suspensions, most of the load due to the weight of the car goes to the body in the place of the upper mounting of the telescopic rack, since the elastic element (in the figure this is a spring) is located directly on the front rack.
The lower lever of a triangular shape is needed to control the trajectory of the wheel and to transmit to the power elements the longitudinal and transverse forces that appear when the car is moving. A similar system works well if front-wheel drive is installed: the axis of rotation of the wheel will be located above its lower arm.
Typical malfunctions of the front suspension arm
To know how to remove the front suspension arm, you need to understand its structure.
The types of front suspensions that have been used recently are complex energy-intensive multi-link devices. They are created from components of various configurations and materials.
The front suspension arm is the main part of modern multi-link devices, which can be divided into the following types:
- Subframe : This is a rigid base on which several mounting holes are located. It is required to install the transverse rods.
- Trailing arm: responsible for fixing the wheel when moving back and forth (Y axis). The lever is attached to the body and the hub support. Fine tuning of the longitudinal elements avoids yaw. In addition, these parts also allow you to fix the position of the body with possible sharp accelerations and braking.
- Transverse lever: this element of the front suspension is necessary to provide the desired range of displacement of the body along the X axis. That is, the transverse elements of the suspension are responsible for the body rolls.
It can be said that in multi-link front suspensions, which are actively used now, the active elements are mostly blocks of three elements, and not levers separately.
There are two types of compounds: A- and H-type.
In addition, the levers are upper and lower. This division is relevant for the front suspension. They perform such functions:
- The upper front suspension arm is responsible for fixing the steering fist and its connection with the wheel. Due to the rigidity of the connection, the vertical position of the wheel is ensured.
- The lower front suspension arm can partially relieve the load from the upper, taking over the work. In addition, it does not allow the McPherson type rack to go beyond the permissible range of vibrations.
Car owners can often experience the following problems:
- when driving on a slightly rough road, their front suspension “breaks through”;
- the car constantly steers right or left;
- tires wear out very much (they can be worn to cord yarns).
If you are faced with the aforementioned troubles, then this may indicate problems with the front suspension arms. In the case of “punching” the suspension, the fault may be a kink of the lever. If at least one of the three levers in the A- or H-unit fails, the suspension’s energy consumption immediately drops. Just in case, you should check the springs, their integrity.
If the car constantly goes left or right, you need to make sure that the front suspension arms are intact. The metal rod could be bent during operation.
Most attention should be paid to the places where the levers are connected to the rest of the components.
In the event that the tires become unusable too quickly, the crashed wheel alignment angle may be to blame. Since the wheels have already lost the desired vertical position, the rubber begins to wear out a lot. If you cannot correct this angle, you can look for a problem in the place of attachment of the front suspension to the steering knuckle. It is likely that the fasteners or seals are deformed.
The state of the front suspension arms is also affected by the wear of the silent blocks. These parts serve for a long time (on average up to 175 thousand kilometers), but their resource is spent if the car is operated in difficult conditions or if the factory was overlooked and the scrap was not removed from the conveyor. The consequences of wear of the silent blocks are the same: the car skids or the rubber erases a lot.
Silent blocks absorb the vibration that occurs during the movement of the car, and thus they prevent the remaining parts of the front suspension from breaking. If you want to check the condition of these parts, you will need to unscrew the ball bearings, driving the machine into the inspection hole. Ideally, they should not have any cracks and tears, and the material itself should be elastic and dense.
If the structure of the material has changed (the rubber is already loose and wrinkles easily in the hands), then they need to be removed and new ones installed.
In addition, pay attention to the bush of the silent blocks – it should not rotate, no matter how much effort you make.
How to remove the front suspension arm
To remove the front suspension arms and the silent blocks, and then install new ones, you will need:
- device for extruding / extruding silent blocks;
- set of cap and socket wrenches;
- jack;
- balloon wrench.
Work can be carried out on a viewing hole using a jack or on a lift.
Motorists may need to remove the front suspension in three cases:
- To replace the cradle.
- To replace the silent blocks.
- To replace the lever axis.
To understand how to remove the front suspension arm (upper), follow our instructions.
You need:
- Drive your car into a viewing hole or lift.
- Using a balloon wrench and a jack (if you are on a viewing hole), remove the wheel.
- Then remove the bolt that holds the front bumper bracket.
- Unscrew the self-locking nut and mounting bolts, then you will be able to disconnect the upper ball joint.
- Holding the axle with a wrench, remove the self-locking nut from the lever axis.
- Then take out the axle.
- Remove the upper lever.
If you removed the forward gear lever and saw that it is in order (not deformed and there are no cracks), it can be reused, but first you must remove the silent blocks and install new ones. To do this, you need to extrude them with a puller. At the same time, make sure that the lever is tightly clamped in a vice.
Before returning the part to its place, it is necessary to press in the new silent blocks using a puller. To do this, change the position of its elements on the lever.
Before the lever is installed, it is also recommended to remove the self-locking nuts of the lever axis and the ball joint pin and install others.
When working with a lever, follow this sequence of actions:
- Install the lever on the axle and do not tighten the nuts. Lock it.
- Install the bolt that is responsible for securing the front bumper.
- Lower the jack / hoist and give the suspension a load.
- Swivel the ball joint finger into the knuckle.
- Then tighten the self-locking ball nut.
- Tighten the nut securing the axis of the upper arm.
- Lift the machine and install the wheels.
After the replacement procedure, the descent angle should be checked.
As with the upper link, you may also need to remove the lower front link arm to replace the silent blocks, axles, or the link itself.
All manipulations are carried out on a viewing hole or lift.
Operating procedure:
- Raise the machine (on the jack or use the lift).
- Remove the wheel from the machine.
- Remove shock absorber.
- After that, you need to unscrew the nuts of the lower arm.
- Then you should disconnect the stabilizer mount.
- Lower the jack or lift, thereby loading the machine.
- The next step is to unscrew the fastening nut and press out the finger of the lower ball joint from the knuckle.
- Then, along with how you will transfer the stabilizer through the mounting pin, you need to remove the load from the front suspension.
- Pry off the spring and remove it from the support cup.
- Unscrew a few self-locking nuts that secure the axis of the lower arm.
- The next step: remove the thrust washers.
- Then remove the axis with the mounting blade.
- Remove the lower ball joint; if necessary, change the lever. To do this, unscrew the mounting bolts. It is only necessary to remove the support to replace the lever.
- Lock the lever in a vise.
- Using a puller, press out silent blocks.
If you removed the lever and see that it is intact, you can simply remove the old silent blocks, change them and assemble the assembly back. In this case, it is necessary to remove the self-locking nuts and install new ones.
It is important to note that one and the same puller is used to press and press the silent blocks, it all depends on the location of the parts and the lever relative to each other.
To put the lower lever back in place:
- First press in only one silent block.
- Insert the axis into the lever on which the thrust washers are located.
- Install the thrust washer on the side where the bushing is located and tighten the self-locking nut, but do not tighten it.
- Press in the second silent block.
- Install the shaped washer on the axle and tighten the self-locking nut.
- Establish all elements of a forward suspension bracket (including the lever) in reverse removal of sequence.
- Having loaded the front suspension, tighten the nuts on the lower arm axis well.
- Reinstall the wheel.
When you have finished replacing the silent blocks and / or lower arm, check the wheel alignment and adjust if necessary.
Important note: silent blocks wear out quickly if oil gets on the rubber, as it is not oil resistant. Find the cause of the oil leak, fix it, and then you need to remove the old parts and put fresh ones. Otherwise, the problem will be repeated.
