Tuesday, March 25, 2014

Front End Alignment:

Front end alignment is the head of car alignment. 
Generally wheel alignment is the way to keep your car in your hand and keep your money in your bucket. But after a while your car has to go to the mechanic, it needs an operation in its wheels and doctor technician is ready for the surgery. 

Cars body is loaded in four wheels and the four wheels must be perpendicular to the ground and have one leader so that the car can go straight. What the technician does is adjusting wheel angles and in the case of front end he will deal with three main angels:


1-  Camber angle.

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Generally the function of the camber angle is to prevent vibrations and shocks from reaching drivers hand.
 It is the angle made by the wheel side plane and the ground and it is measured by degrees. 
There are two cases for this angle; the first when this angle is less than 90 D then the angle is negative, in the other case when it is larger than 90 D then it is positive.

The difference between the positive angle and the negative one:

The positive angle is useful in compensation for the weight of the car and the passengers on the axis and reduces the effort done by the driver in order to control the car especially outside the roads.

The negative angle is useful in balancing the car on the road as on the inclined roads.
When the car is turning hard curve the inside half of the outside tire will rise on the ground so the angle will compensate this raise so that it will be more stable and fixed on the road.

Problems and results:



A-  Positive camber angle is too much:
-          Erosion in the tires from the outside.
-         Severe corrosion in suspension parts.

B-  Negative camber angle is too much:
-         Erosion in the tires from the inside.
-         Severe corrosion in suspension parts.

C- Inequality in the two side’s angles:
-         The car will deflect towards the wheel that has the bigger angle.

2-Caster angle:


Caster angle is the first angle to be corrected when doing wheel alignment.

It is the inclination angle of the steering axis of wheel forward or backward for vertical level when viewed from the side of the car. It is measured by degrees.





There are two cases of this angle:



-         When the steering axis is towards the rear end of the car then it is positive.
-         When the steering axis is towards the front end of the car then it is negative.


The purpose of this angle is to make the car go straight by itself while on long or highways. 
It is easily affected by car height that must be kept because overriding loads on the car or the weakness of the rear spring badly affects the angle.

Recently most cars have positive caster angle which has the value 2 degrees and may reach 10 degrees in some cars so that it aids the camber angle and this ease for car driving and make the driving wheel return to the initial position after passing curves. 

 Problems and results:



A-  Positive caster angle is too much.
-         Difficulty in routing.
-         More sense of the pitfalls of the road:
-         Tire vibration.

B-  Negative caster angle is too much:
-           Difficulty in controlling the car.
-           Car deflection from one direction to the other.

D-   Inequality in the two side’s angles:
-         The car deflects towards the wheel that has the small caster angle.


In recent cars the caster angle and the camber angle is Non-adjustable.
For the axes types; the caster angle changes, as in case of Front-wheel drive the angle is negative and in case of Rear-wheel drive it will be positive these values make the wheels go straight and this increased by the speed.


3-TOE  angle:




It is the inclination angle of the wheel to inside or outside and is measured by the deference between the front of the tire and the rear of it. It is almost sets at zero and the wheels are parallel.

 There are two cases:



-         When the distance between the fronts of the tire is less than the rear of it, in this case the angle is TOE IN.


-         When the distance between the fronts of the tire is bigger than the rear of it in this case the angle is TOE OUT.





Problems:


In case of TEO misalignment the two tires will be Eroded together and the shape edges of Corrosion look like the teeth of the saw
If this edges is towards inside then the problem is that the angle TOE IN is too big, and if the edges is towards outside then the problem is that the angle TOE OUT is too big.

The purpose of TOE angle is to cancel the effect of camber angle as when the camber is positive and when the car moves the wheels will try to deflect outside so that the toe angle is set towards inside in order to compensate the effect.   
The TOE angle is the last angle to be adjusted.

wheel alignment is also done to the rear wheels, but the front end alignment is more important because it is more complicated and contains more angles need to be adjusted.  

blogged by: Salah Ghanem.
 

3 comments:

  1. I hadn't given alignment much thought until I had it done to a car I was driving. Before it had been done, I had to keep twitching the wheel to go down a straight road. After it got aligned it went so straight I can practically let go of the wheel and it will stay right where it should.
    http://www.medinamuffler.com/Automotive_Repairs_Preventative_Maintenance_Medina_OH.html

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  2. This was a very informative post. My car's wheel alignment needs to be corrected. My husband tried doing it himself, but that just made it worse. I really need to take it in to a professional.

    Susan Hirst | http://www.eastcarolinaautos.com/Car_Maintenance_and_Repairs_Indian_Trail_NC.html

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  3. Nice Post.
    Informative and important information is here.
    Thanks for sharing !
    Wheel Alignment

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