DIY automotive repair : How to diagnose suspension problems.

Suspension issues in a vehicle can easily be overlooked by the average driver. However these problems can also cause severe damage, as well as extensive repairs.

Shocks and struts are the most obvious component in a suspension system. The purpose of these are to keep your tires on the road, and to obviously absorb the spring action from bumps in the road. There is a very simple, but conclusive way to test these. Simply push down, and let it come up until the car is bouncing, and when you let off, if the car rebounds more than once you are experiencing soft shocks or struts.

You may also notice that when driving at highway speeds on rough roads that the car feels like a boat on water. Actually, it may feel like a very smooth ride, but all that extra rebounding of the suspension as a whole is not good for the other components of your suspension. Also, when taking exit ramps you may feel as though the car leans excessively. Bad shocks and struts will also cause "cupping" of tires. Cupping is when one block of the tread stands out more than the next. Run your had over your tires if they don’t feel smooth you probably have an issue. These are all good signs to take a look at those struts.

When replacing the strut, you will have to have the spring pressed off of the assembly as it is one whole unit. There are products out there that come as the whole assembly, check in to these, they may cost some more, but will save you in labor and extra time down the road.

Ball joints sit at the bottom of the strut tower and are a very common suspension issue. They are at the end of the lower control arm. The best real test for these will require a partner. First lift the car in the air so that the tire is free from the ground. Have a partner with a flashlight look at the ball joint from behind the tire as you wiggle the tire up and down. If you have a ball joint problem your partner may notice that it spreads apart slightly. If the ball joint spreads GET IT FIXED! While you can drive a car with bad ball joints, all it may take is one bad pothole to let that ball joint spread to far and the tire will collapse underneath the vehicle.




Now before you let that car down check the tie rods. There are inner and outer tie rod ends. The outer ends connect the steering arm to the hub assembly. The inner ends connect to the steering box. These also are a very common issue. Simply keep your partner where he is and now wriggle the tire side to side. If you have a tie rod problem, they will feel loose as you wriggle the tire. Have your partner hold them as you do this and if they feel any play, or looseness at all, you may have a problem.

Both ball joints and tie rods should not move under the power of a human shaking them. They are designed to pivot tightly, and any play in either of these can be hazardous. When either of these parts goes bad you may feel a slight shimmy when turning under acceleration, or when steering through turns. Both will cause misalignment, and uneven tire wear.

Hopefully this will help diagnose our suspension issues as these are the most common issues we may be faced with. Its surprising how simply they can be diagnosed when you just have the right information! Cheers my friends. :)

simulator vehicle suspension works

how vehicle suspension works

The oscillation was the dangerous thing. So, what they did is, they produced the thing called a shock absorber, which damped the oscillation. In other words, it would oscillate, and then very soon, it would come back to its original position.

So, the vehicle would jump up when it hit a bump, and then it would rock back, and then come to a stop. And if it was a level road, with just one bump, after less than a second, it would be traveling normally again.

To do this, the shock absorber is constructed in this way. Basically, it's a cylinder. Here an empty cylinder, filled with oil. The piston at the bottom, when some shock hits it, the piston moves upwards, into this space, pushing oil out into a reservoir. When the, when the force is released, the oil returns to the reservoir, but quite slowly. Then, instead of suddenly going up and down, this reduces the tendency.

This stores the energy, which has been produced by hitting whatever bump you hit, and it stores that energy and releases it gradually. So, it means that the oscillation is now a damped oscillation. It in fact, stops this continuous oscillation, which was so difficult in the past. So, on all of the vehicles you will travel on, whether it's a rail, a train, whether it's a coach, or whether it's a bus or a car, there will always be a shock absorber on each wheel.

And that shock absorber will make your journey very much more pleasant and safe.

Adjustable Suspension for Mcpherson type

Adjustable absorber

Adjustable Suspension

There are many type of suspension that we know, there are also suspension for better use. Which mean for racing use or aftermarket product. Some adjustable are for high or low adjustment, this type is usually release by aftermarket manufacturer or tuner. There are many brand of adjustable like Tein(which are most common use for many type of car), Blitz, Hotbitz, Gab(was usually for budget car because of the price that being bargain) and many more type of the brand.

Height adjustable suspension is a feature of certain automobile suspension systems that allow the motorist to vary the ride height or ground clearance. This can be done for various reasons including giving better ground clearance over rough terrain, a lower ground clearance to improve fuel economy at high speed, or for stylistic reasons. Such a feature requires fairly sophisticated engineering.

Usually for road race car, they are using adjustable suspension for adjust the height, so that they can use different size of rim. If want to change the rim even bigger, there is no need to change spring coil due to the height.like 15 inch rim, the tire profile in range 195/60/15 so the gap is quite big then the suspension can be adjust to lowered it. But if the driver want to change to rim 17 inch, the tire profile also change like 235/35/17 so the suspension must be adjust at higher level. This was regarding to the manufacturer and type of car,rim,and clearance of the gap.

This is one of the type of adjustable suspension
TEIN's Type FLEX damper kit was designed to provide driving comfort and sports performance with its full-length adjustment system. They have incorporated separate height and preload adjustments, which allows you to have various set-ups to meet different road conditions. The FLEX Damper kit includes pillow ball upper mounts and is compatible with the EDFC, for maximum performance for the streets.

TEIN Flex Coilover Features:
• Full-length adjustment and height adjustment for separate setting of the height and spring preload
• 16 levels of damping force adjustment (compression and rebound together)
• Teflon coating for rust prevention
• Newly designed spring seat and spring seat lock for easy height adjusting
• Pillow ball upper mounts are included
• Compatible with EDFC - so you can adjust your suspension inside of your car while driving

Gab adjustable suspension

Full TEIN car adjustable front and rear absorber

Suspension and Conering

During conering,suspension was play an important role as a weight transfer from body role.Which mean during cornering the suspension absorb the body from moving left and right,where we call it as rolling in automotive studies.As vehicle rolling the driver and passengger will feel uncomfortable,(suspension system is not only for safety but also provide comfortable driving) the car actually like bouncing left and right,then right and left.

If there are to many rolling for the car,driver will lose control if taking in or enter corner to fast,then crach will happen.For safety reason there is why manufacturer provide better suspension system in every new model release.Usually nowadays they use MacPherson strut,Double wishbone and multi link suspension/semi-trailing arm type.

The very important job of a suspension system is to smooth out the ride while maintaining excellent control. This may sound like a simple job, but with acceleration comes force, and force translates into raw energy. When a vehicle accelerates down a road, bumps cause forward energy to be converted into vertical energy, which travels through the frame of the vehicle. Without coil and leaf springs(usually MacPherson type) to absorb this, the vertical energy would cause the vehicle to jump up off the road, reducing tire friction and control. The car would then come bounding back down with even greater force, making for a very uncomfortable and dangerous ride.

Below is the example of the suspension system for independent system:

MacPherson strut type:

This system is usually use for most widely in independent suspension system for small and medium sized cars.These type are so popular so in FF(Front engine and front wheel transmission)type of car,used as the rear suspension.


Characteristic for MacPherson:

The construction of the suspension is relatively simple.

MacPherson type,have small number of parts,so when it component is less,then less weight.The effects is unsprung can be reduce.

The space for the suspension is small,the usable space in the engine compartment can be increased.

Since the distance between suspension support point is great,there is a little disturbance of the front wheel allingment due to installation error or part manufacturing error.Therefore, except for toe-in,allingment adjustment ordinarily unnecessary.

Spring Offset:

On the MacPherson strut type suspension, the shock absorber act as part of the suspension linkage, bearing the vertical load.However, because the shock absorbers are subjected to the load from the tires, they bend very slightly.

This cause lateral stress (A and B, as shown in the illustration) to be generated,creating friction between the piston road and the road guide, and between the piston and inner shell, causing abnormal noises and adversely affecting riding comfort.

These problem can be minimize by off-setting the spring from the centerline of the strut or shock absorber so that reactive forces a and b generated in opposition A and
B.

Double wishbone type:

This is usually used for front suspension for small trucks and for front and rear suspension for passenger cars.

Characteristic for double wishbone:

Wheels are mounted to the body via upper and lower arm.

Suspension geometry can be designed as desired according to the length of the upper and lower arm and their mounting angles.

For example if upper and lower arm are parallel and have equal length,the tread and the tire-toe ground camber of the tire will change.As a result,it is not possible to obtain adequate conering performance.In addition, in the tread will cause excessive tire wear.

To solve this a design is normally employed in which the upper arm is made shorter than the lower arm so that the tread and the tire-to-ground camber of the tire fluctuate less.


Semi trailing arm type:

Is used for the rear suspension in a few models.

With this suspension,the amount by which the toe angle and camber change(due to the up-and-down motion of the wheels) can be controlled at the design stage, in order to determined the handling characteristics of the vehicle.

An Introduction

Safety system was one of most important role in automotive industry. Manufacturer must follow the goverment legislation. Legislation is use as a mark to followed by the manufacturer. One of the important thing in safety is the suspension system. Suspension connects the body or chassis of the vehicle with the wheels.Function of the suspension is during running the suspension absorb various vibration,oscillation, and shock receive by the vehicle. Suspension also transmits the driving and braking forces,improve driving stability and support body on the axles.It consists of the following principal components such as springs that neutralize the shocks from the road surface, shock absorbers(dampers) acts to improve riding comfortby limiting the free oscillation of the spring, stabilizer(sway bar or anti-roll bar)prevent lateral swaying of the vehicle, a lingkage acts to hold the above components in place and to control the longitudinal and lateral movement of the wheels.

There are 5 types of suspension
• Leaf spring

• Coil spring

• Torsion bar spring

• Rubber spring

• Air spring