Any motorist, hearing any incomprehensible sound made by a car, for example, a click or knock in the front suspension area, experiences unpleasant associations. When heard knock on the front suspension, this is a clear sign that there is a problem with the vehicle’s chassis. If the car suspension rattles, then you need to immediately make running diagnostics car parts.
The main reason for the failure of a car’s suspension is, of course, a broken road, the suspension breaks most often due to very unpleasant “surprises” such as holes and ditches. The suspension begins to knock after the car flies into a hole or on a bump, in the same way the suspension breaks due to inexperience, when some drivers notice a pothole at the last moment, and immediately press the brake pedal to the floor and do not release the pedal when the wheel hits into a pothole – during braking, the load on the rack increases several times and, accordingly, the suspension also suffers several times more. A considerable influence on the operation of the suspension is given by the angle of rotation of the wheel when hitting a pothole, but the reason is the same, increased load.
What suspension elements need diagnosis
So, what should you do if you appear knock on the suspension, and also talk about the reasons for its occurrence. First of all, you need to clarify something … If the suspension rattles, then this is the result of a malfunction or improper operation of any part or the chassis mechanism, for example, it may fail:
- Shock absorber;
- Spherical bearing;
- Lower arm with silent block;
- Upper suspension support with bearings;
- Stabilizer link;
- Stabilizer support;
- Steering rack;
- Tie Rod;
- Steering tips;
- Hub bearing;
- Steering cardan;
- CV joint (outer joint).
It will not be possible to determine the malfunction by ear, just as to find the source of this knock in the front suspension, in order to find the malfunction, it is necessary to conduct a thorough diagnosis.
Visual diagnostics of the front suspension
Before you start checking the suspension parts, you must first inspect all the anthers and rubber covers of all the listed parts, as well as: silent blocks, ball joints, front suspension arm, anti-roll bar, steering knuckle, mounting bolts, as well as steering tips traction. As a rule, the part, the cover of which is damaged, needs to be replaced.
It is also necessary pay attention to rubber seals, they should not have any mechanical damage. Particular attention should be paid to those places where parts adjoin the body.
Leaks on the shock absorber
When it is seen that the shock absorber has leaked, this is the very first sign of its malfunction. These symptoms appear much earlier than other symptoms, such as scratches and extraneous sounds when rocking..
In oil and gas-oil shock absorbers, oil first seeps out from under the rod or the strut body, and after a while, dull blows appear.
Also, it should instantly damp vibrations, and not swing, as it happens with a gradual failure. For some time the shock absorber may still work normally, but it will still be better if it is replaced.
Checking the front suspension elements
Sagging (worn out springs) have a great impact on the overall performance of the suspension. When the springs wear out, it can be easily identified without a tricky diagnosis. It is enough to carefully inspect the car from all sides and turn your attention to the landing of the car. If it has become lower than usual, then the springs have already served their purpose and need to be replaced. With sagging springs, it becomes impossible to correctly adjust the camber.
To check the ball joints, you can check how the lower arms move up and down. Such check must be carried out at the inspection pit using a pry bar. There should be no tangible backlash.
When you press the mount on the silent blocks of the lower levers, there should also be no backlash, and cracked or squeezed out pieces of rubber are not at all acceptable. It is also worth paying attention to whether or not the rubber is peeling from the outer or inner sleeve..
How to diagnose suspension
To check faulty ball and silent blocks, you will need to raise the car on a lift or jack and unscrew the ball joint to the lower arm, then turning the ball joint housing with your hands, determine how smoothly and with what force it turns, any backlash is unacceptable. The lower lever, due to the effect of the elasticity of the rubber of the silent blocks, should try to take a horizontal position.
Malfunctioning bearings can often be identified by swinging the machine up and down, if unsuitable, they will have backlash. It is not always possible to identify the broken rubber part in the suspension support without removing the support.
Therefore, when visually checking the linkage and stabilizer support, you need to swing your hands with effort.
Backlash is not allowed on all connections.
Steering rack failure is quite rare. Basically, it breaks down due to wear of the guide sleeve, on the side opposite to the driver. To determine such a defect, you need to turn the steering wheel to the side and swing the rail with your hands through the cover.
Checking the steering tips and tie rods can be carried out by turning the wheel left-right with your hands or by the steering wheel, but at the same time, you must simultaneously grasp the part being checked. Backlash on the tips and on the rods should not be observed.
With a faulty steering cardan, it can either play or rotate with some effort. It is necessary to make sure that the steering cardan is covered with a cover, it is advisable to pick up and put on some cover-cover if there is none.
Hub bearing malfunction accompanied by hum when driving. To check the wheel bearing, you need to hang out the wheel and spin it or swing it beyond the upper point, in the direction both from you and back.
External CV joint
A faulty external CV joint emits a rather loud and characteristic sound, accompanied by a crackling sound when the car is moving in a tight corner with slight acceleration.
Front suspension may also have a number of other faults, but only the most typical ones were considered.
Detailed car suspension diagnostics on their own, it will make it possible to identify the malfunction and begin to eliminate the defect and repair the suspension without extra spending of money and time. The verification process can be carried out both in your garage in the inspection pit or just outside. Having carried out your own diagnostics, you will be able to conclude whether the car’s suspension needs capital and the replacement of some parts of the nodes or a small tightening of the connection bolts.
And in conclusion I want to say that having discovered malfunction of the chassis, do not delay repairing it, since your own safety and the safety of your passengers on the road directly depends on the state of the car’s suspension.
Author: Ivan Petrovich
Ask in the comments. We will answer necessarily!