Did You Know?
Control arms have been used in automobile suspensions for close to a century.
Most people consider a vehicle’s entire suspension system as ‘one’ part. The fact is, it is made up of several components which play different roles. One such component is the control arm, which is mostly found in the front wheels, though some trucks and cars have it in the rear ones too. It connects the front suspension of the vehicle to its frame. There are two control arms in the suspension―upper and lower―and they contain a rubber bushing at the end. This is made up of a rubber lining encased between two metal sleeves.Such placement and compact design of the bushing is done on purpose; it helps cushion the vehicle from small bumps and vibrations, which a spring cannot. The inner metal sleeve is connected to car frame via a center bar. The outer sleeve is connected to the wheel assembly via the control arm. Thus, both the sleeves move independently from each other, and it is the rubber bushing which provides a lubrication between them. Considering that they bear a huge amount of stress with every drive, these bushings wear out pretty fast by becoming hard and cracking. Let us see how to identify a bad control arm bushing from its symptoms.
Steering problems are one of the first indications of a damaged control bushing. The steering may lose a bit of its responsiveness. At high speeds, it may even start ‘wandering’, or make the vehicle turn erratically. The driver can feel the wheel vibrate while in motion. The vehicle may start leaning to one side, to some degree, when taking sharp turns.
A bad bushing will compromise
Did You Know?
Before the invention of the speed gun, cars in the early 20th century were required to have two speedometers, one on the dashboard and one on the front fender, so that police could see how fast they were going!
A speedometer is an instrument which provides the driver with instantaneous readings of speed. Traditional speedometers used gears and wires to determine speed, while most modern vehicles use speed sensors for the same. Common problems include, a faulty sensor, bad wiring, or dial malfunctions. Troubleshooting speedometer problems mostly call for a replacement of the speed sensor or cable, depending upon the vehicle. Both these repair jobs are simple to perform and can be done at home.
Common Speedometer Problems
My speedometer is dead!
This could be due to two reasons. In older cars a break in the cable that connects the transmission to the speedometer is the most common cause. Cars produced after 1990 are usually equipped with speed sensors, which may crash and cease to transmit speed readings to the speedometer. A more serious problem could be a faulty speedometer head, which needs expert diagnosis.
The ‘check engine’ light came on after the speedometer stopped working
A problem that occurs with digital speed sensors is that they may malfunction and stop sending data to the car’s computer. When the computer tries to calculate road speed it does not receive any information, and as a result the ‘check engine’ light glows.
Replacing the speed sensor will solve this issue, however, if the ‘check engine’ light is not on, and the speedometer behaves erratically or stops working, it is recommended to try the cruise control system in the car, as it uses the same sensors.
If cruise control is working, and the check engine light is on, it may indicate a problem
Modern cars, trucks and caravans are well-equipped with every comfort one can imagine. All these appliances and the engine need loads of electric power to operate. Where does all this power come from? This requirement is satisfied by a very simple gadget, known as the ‘Alternator’. It is short for ‘Alternating Current Generator’. The efficiency of these devices is around 50 – 60%. Through the use of the alternator, which is a dynamo, your car generates its own electrical power and stores it in a rechargeable car battery. Ergo, it’s absolutely essential that you keep a check on the working of the alternator or you may be left high and dry with no power to drive your car!
How Does the Car Alternator Work?
The alternator creates electricity by exploiting a fundamental law of electromagnetism which is – ‘Changing magnetic field creates an electric field’. There are two important parts of the alternator – stator and the rotor. The rotor is essentially a set of three pairs of electromagnets with opposite poles facing each other, placed on a cylindrical disc. They are 120 degrees out of phase from each other. Stator is the stationary part placed at the center of the rotor disc.The rotor is attached to engine crankshaft, by a belt. Thus, an important part of this assembly is the alternator belt, which transfers engine torque to the rotor. When the engine is operational, crankshaft rotation makes the rotor go around. The revolving rotor creates a changing magnetic field. This field induces a three phase current in the central stator. A current is generated 120 degrees out of phase, by each of the magnet pairs. There are output terminals attached to the stator with separate windings for every phase.However, this output current is AC (Alternating Current) but the car accessories
Detecting the noise in wheel bearings can be a tricky job. However, with the correct understanding of how to diagnose the problem, it becomes easy to solve noise-related issues in wheel bearings. A rumbling or cyclic noise can be heard in wheel bearings with problems in their smooth functioning. If the driver senses even a slight problem in the smooth running of wheels, he should go for wheel bearing noise diagnosis. If the problem of bearing noise is not addressed in a timely manner, it can hamper the functioning of wheels.
Identifying Wheel Bearing Noise
The noise emanating from wheel bearings can differ from wheel to wheel depending on the degree of damage caused to them. At first, the noise originating from wheels might sound like a whistle. However, if the problem worsens, the noise could grow louder. Therefore, it is necessary to find out the exact cause of noise.
▶ A common trick used for identifying problems associated with wheel bears is checking whether noise heard at the time of acceleration and deceleration remains the same. One should drive the vehicle along a circular path, both clockwise and anti-clockwise, in order to find out which of the wheels (left or right) emits the sound caused by a damaged bearing.
▶ The noise originating from a wheel bearing doesn’t change with changing speeds; however, it might increase or decrease at the time of turning. Therefore, one can say that the noise heard at regular intervals, while driving at a steady speed, is a sign of problem associated with bearings.
▶ Do not confuse wheel bearing noise with that produced by a damaged CV joint; both the problems are different from each other and they need be dealt with separately.
▶ Noise produced by wheel bearings is a result of lack of