Wednesday, March 26, 2014
Wheel Alignment
There are many problems we may face during driving such in
motor, suspension, brakes, light, battery or wheel alignment and others. It is
very important to know what your car need is, so that you can drive safely.
In case of your car needs wheel(s) alignment:
First how can you know that your car needs this?
There are many Signs you can feel it while driving, especially at high
speed:
1- Your car deflections to left or right as a result of
non-parallel tires vertically or horizontally, and called the lack of
discipline of corners.
2- You may feel the vibrations in driving wheel at high
speed so your car needs Balancing.
3- When you hit a pothole you may hear noise from wheel(s).
4- Erosion of Tires inside or outside.
Wheels Angles:
The term "wheel alignment" is involving two
main measurements.
1) Primary:
- Caster: It is the Inclination of the axis of steering wheel for vertical
level, backward or forward.
- Camber: It is the inclination angle of the wheel for vertical level, about the
axis of the wheel of accidental.
- Toe: It is the inclination angle of the wheel for vertical level, about the
vertical axis of the wheel or The distance comparison between the leading edge
and trailing edge of the front tires.
2)Secondary:(S)
1- S A I (Steering Axis Inclination)
(left & right). The angle between true vertical and a line drawn between the
steering pivots.
2- Included angle (left & right). The sum of the (S A I) and the camber.
3- Toe
out on turns (left & right). The amount of toe-out present in turns.
4- Maximum
Turns (left & right).
5- Track
width difference.
6- Toe curve change (left & right).
7- Wheelbase
difference.
8- Front
ride height (left & right).
9- Rear
ride height (left & right).
10- Frame
angle.
11- Setback
(front & rear).
There are standards
for these measurements are used by technicians as targets of adjustment. So you
must get close to the right measurement. We will take them in detailed later.
Causes of angles misalignment of the wheels:
There are many reasons can make misalignment in car
wheel(s). Some of them are Caused by Neglecting small signs, or passing long
time with hard working without rest. Or maybe:
1- Non equal erosion to the internal or external half of the
wheel and this reduces tire's lifetime.
2- Passing the hard curves on highways at high speed.
3- The status of the road In terms of the decline in the
right or left as the car will be loaded on one side this effect on the wheel
angles.
4- The Pressure inside tires is variable from one tire to
another this also makes the car load on one or two wheels.
5- The status of tires in terms of size, equality and
Quality.
6- The car subjected to an earlier incident and led to the
disruption of chassis size in this case it’s very difficult to fix these
issues.
What happen if You did not fix this problem?
1-
Your life will be on the line cause at high speed this problem becomes very
dangerous.
2-
Fuel consumption will increase.
3
- Tires and suspensions lifetime will reduce.
4-
Weakness in vehicle stability.
Steps to prevent wheel
misalignment:
1- Go immediately to check for wheels balance and stability
as soon as you see any sign shown.
2- Prevent passing curves quickly.
3- Prevent passing holes and pothole with high speed.
4- Regular Detection on car systems protects you from sudden
flaws.
5- Always check the tire status.
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:
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.
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.
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.
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.
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.
blogged by: Salah Ghanem.