Symptoms of a Bad Control Arm Bushing

Symptoms of a bad control arm bushing
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.
Drive Comfort
A bad bushing will compromise driving performance and comfort. Since the purpose of the control arm bushing is to cushion against small bumps, a damaged one will not be as effective, resulting in vibrations throughout the drive. In case of extreme damage, when the rubber bushing is completely worn out, the metal sleeves of the control arm will begun to rattle, resulting in an unpleasant ‘clunking’ noise from the front end, especially while turning or reversing. Moreover, the wheel with a damaged bushing will begin to wobble while driving.
A sudden improvement in braking efficiency can, as strange as it may seem, be attributed to a damaged control arm bushing. This is because the forward and backward oscillation of the control arm is not achieved during braking due to bushing wear. However, this effect will not be constant, making braking unstable. Moreover, when the vehicle is braked suddenly, the front end will continue to oscillate forward.
When accelerating from a static position, a backward movement will be observed in the rear end of the car, along with the problem of erratic steering, as explained above. When speeding, or taking a turn at slow pace, the steering starts trembling, and a tugging effect is observed.
Test Drive
Take the vehicle for a drive, preferably on an empty stretch of a freeway which allows for rapid speeding, extreme turns of the wheel, and momentarily abandoning the wheel. If you observe a clunking sound, vibrations, or wheel misalignment, then this indicates a problem with the control arm bushings. Extreme maneuvers with the steering can also be tried on a large, vacant parking lot.
Wheel Alignment
A defective bushing can be checked by raising the car with a jack, or on a lifting platform, and pressing the wheel by hand. If it shows a great degree of ‘play’, meaning that if it wobbles sideways more than usual, the control arm bushing needs replacement.
Axle Slip
The vehicle can be raised on a lifting platform, and someone can apply the brakes to stop the wheel from moving. On turning the steering from left to right, someone else can observe the axle. A damaged bushing will make the axle ‘slip’ momentarily during the turning motion.
Prying Control Arm
Raise the vehicle using a jack, and using an 18″ pry bar, pry the control arm from side to side. Ideally, it should ‘spring’ back from the position it was pried to. If this doesn’t happen, and the control arm stays in its new place, the bushing is at fault. Also, observe the edges of the rubber bushing by prying aside the metal sleeve. If the control arm is not centered within the bushing, the bushing definitely needs to be replaced. A few cracks on the bushing ends are not something to worry about.
Uneven Tire Wear
When there seems to be a problem with a wheel, raise that end with a jack and get under the vehicle. Observe the edges of the tire. If it is wearing out unevenly, either from the inside or the outside, this is due to a wheel misalignment caused by a bad control arm bushing. The central tread may also show a scuffed pattern.
Some of these symptoms can also be attributed to worn-out tie rod ends, sway bar links, ball joints, or even the control arms themselves. So, when in doubt, get the vehicle examined by a professional. Whenever a worn out bushing is observed, getting it replaced is a must. Ignoring these symptoms can result in damage to other expensive suspension components. Since these bushings tend to wear out pretty soon, auto experts agree that it is a good practice to replace them once a year.

Speedometer Not Working Properly

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 with the speedometer itself, and may require a change of the instrument panel. A ‘check engine’ light is a serious issue on its own and must be checked immediately.

Bouncing or jerking of speedometer
In cases where the speedometer does not settle on any particular reading but keeps moving between speeds, it is almost always due to bad wiring, in case of a cable system, or a faulty speed sensor. In most cases, only the wiring needs to be changed, or the sensors re-calibrated, to repair the problem.

Changes in the car
Speedometers are calibrated according to the radius and diameters of the factory-fitted tires of your car. These determinants can change, if you get custom tires which are larger, or if they are of different dimensions. The rate at which your tires cover ground changes and if the speedometer is not calibrated accordingly, it can show a faulty reading.

Troubleshooting Speedometer Problems
Instructions for removing speedometer cables
~ Remove the engine cover and take a look at where the cabling enters the main body of the car. You will see a thick black wire leading into the instrument cluster, this is the speedometer cable.
~ Take out the bolt from under the dashboard, so that you can easily access the old cable.
~ Also, remove the nut on the transmission and pull the cable out through the passage. Remove the clamps present on the transmission and engine compartment that hold the cable in place.
~ Once you have removed the old cable from your car, you need to replace it with a new one. In the adapter, fix the square end of the new cable and also tighten the nut on the rotating shaft.
~ Now, pass the new cable through the passage and tighten the bolt at its rear end. This end should be fixed at the speedometer’s square hold.
~ Fix back the clamps you earlier removed, and also put back the engine cover.
Replacing speed sensors on front wheel drive vehicles
~ You will find the speed sensor behind the engine, above the trans-axle.
~ Remove the connecting hose, air cleaner and electrical connector from above the sensor.
~ With help of a 10 mm socket, remove bolts keeping the sensor in place. Then, twist the sensor to take it out.
~ Attach a new O-ring to the sensor and clean the sensor flange and exterior sensor housing before re-installation.
~ Fix the new sensor in place and tighten bolts around it. Reattach the hose, air cleaner and electrical connector on to the sensor.
Replacing speed sensors on rear wheel drive vehicles
~ You will find the speed sensor on the driver’s side behind the transmission.
~ Raise the vehicle up from the driver’s side using a car jack.
~ Remove the wheel.
~ Disconnect electrical connectors present on the sensor and remove bolts, keeping the sensor in place, using a socket.
~ Remove the sensor carefully, and fix a new one in its place. Don’t forget to replace the old O-ring with a new one before installation. Attach the electrical connector to it, and tighten it.
Not every speedometer related problem needs a replacement job. It depends on the cause. In case the dial is the problem, you can easily replace the dial alone. Problems with the inbuilt computer will require replacement. It is therefore important to take your car to a mechanic and run a full diagnostic test, before jumping to any conclusions and attempting self-repairs.