CONCLUSION

In a conclusion, steering system is one of the most important feature in automobile. This system will control all of the direction and movement of the wheel of our vehicle. Besides, the components that are involved in this system are steering knuckle, centre link, anti-sway bar, upper control arm and adjusting sleeve. This components must always in good condition so that steering system will run smoothly and more efficient to provide the driver with good experience of driving on the road. For this group assignment we are given three different type of car manufacturer such as Cadillac, Subaru, and Citroen. Different type of car manufacturer has different characteristic in technology invented and has their own advantages and disadvantages. This characteristic is very important because when we want to buy a car we must know at least how this system works and how this feature can help us to enjoy a good experience of driving in our life.

First of all, in this discussion we are covering on Cadillac automobile. Cadillac type of car preferred on rear-wheel steering system that can control all four of its tyre by active chassis system. Cadillac’s rear-wheel steering system doesn’t just make the car easier to drive in low speed scenarios, it also increase agility at higher speeds. Other than that, by controlling all the tires this car or automobile is easier to handle and can provide more safety characteristic to the driver. The benefit of this active chassis control is switching between comfort, sporty and normal modes, handling performance can be influenced to suit the specific driving situation and driver. Furthermore, if power steering system in Cadillac fail to work the vehicle still can be steered using manual effort this condition can avoid unnecessary death from the failure of this system.

Second, Subaru is the other type of car manufacturer that is given to our group. For Subaru the rotational force that are transferred driver rotational force into a lateral one is the main function of steering system in Subaru’s type of car. Besides, the main characteristic of steering system is power assist. Hydraulic pressure provides added boost at low vehicle speeds to help the driver turn the steering wheel. At this point pressure is reduced when vehicle speeds is higher. Furthermore, rack and pinion steering system is the common one because this type of steering system is more precise because there are only few pivot points and parts. Thus, with only fewer parts this system is lighter and can save more room space for any modification. Although, it has its own advantages there are some disadvantages of using this type of steering system such as leakage, less durability and vibration.

Finally, the last car manufacturer is Citroen. The steering system that have been used is Diravi System. This system also known as “power steering with power assisted return” usually used for mainstream vehicles. As long as there is pressure in the car's hydraulic system, there is no mechanical connection between the steering wheel and the road wheels. A hydraulic power safety prioritisation valve sets hydraulic fluid availability to each circuit in the Citroën system. In a hydraulic system failure, order of loss is first steering, then suspension, then brakes. The advantages of this system are its requires minimal physical exertion in the SM the steering wheel can be turned lock-to-lock with one finger when the car is standing and can be set up permitting vehicle to travel in a straight line without driver input on a constant camber road in still conditions while the disadvantages of this system are the driver must survey visual cues to determine approach of road holding limit and Cannot allow both hands to leave steering wheel when navigating curves  because of rapid self centering.

Based on the given points above its prove that different car manufacturer preferred different type of steering system. Cadillac prefer rear-wheel steering system and active chassis control while rack and pinion steering system is prefer by Subaru car manufacturer but for Citroen the car manufacturer stick with Diravi system. Each one of the steering system have their own disadvantages and advantages but for steering system the mutual characteristic is to provide good driving experience to the driver, make sure the safety precaution is the first thing to do and reduce the probability of system failure.

CADILLAC

CADILLAC

 .      Technology used (‘Active Chassis System’)

Active Chassis System means it is available to steer all 4 tires by adding rear-wheel steering system. The idea, which Honda has been a big proponent of in the past, disappeared from showrooms until Porsche equipped its new 911 GT3 with rear-wheel steering in 2014

.      System operation

a)      The rear wheels can turn up to 3.5˚ in either direction

b)      This system boosts

·         low-speed mobility (in effect shortening the wheelbase)  

·         high-speed stability (by lengthening it)

1              

                               Benefit of technology used

·         making the full-size four-door easier to move in tight spaces and city driving scenarios 

·         easier to drive in low speed scenarios

·         Active-on-demand all-wheel drive is also part of the Active Chassis System, making the most of handling and stability in all weather conditions

·         Cadillac’s rear-wheel steering system doesn’t just make the car easier to drive in low speed scenarios, it also increase agility at higher speeds.

SUBARU

DECADES AGO, SPORTS CARS ESTABLISHED THIS TYPE OF SYSTEM AS DESIRABLE DUE TO ITS PRECISION AND RESPONSE, AND TODAY MOST PASSENGER VEHICLES HAVE IT AS STANDARD EQUIPMENT.

                                           

Glossing over reference to rack-and-pinion steering in specification charts is easy to do. We tend to dismiss it because that’s what all vehicles seem to have. However, other systems do remain on the market. Understanding rack-and-pinion steering and its benefits will contribute to appreciating what makes a Subaru, a Subaru.

WHEN YOU TURN THE STEERING WHEEL

With the action of turning the steering wheel to cause a vehicle to change direction, a number of components come into play. Although enhanced by other systems, here are the basics of rack-and-pinion steering:

The steering wheel rotates the steering column.

The teeth on the pinion gear at the end of the steering column engage with teeth on a rack in the steering gear assembly.

The rack assembly moves the tie rod assemblies to which it’s connected.

The tie rod assemblies push or pull on the steering knuckles connected to the front wheels, causing the direction in which the wheels are pointed to change from one side to another.

The point of the steering system is to transfer the driver’s rotational force into a lateral one that alters the direction in which the vehicle is traveling. The steering force from the teeth in the rotating pinion gear becomes a lateral force via the gear teeth on the rack.

All Subaru steering systems have power assist. Hydraulic pressure provides added boost at low vehicle speeds to help the driver turn the steering wheel. Pressure is reduced at higher vehicle speeds.

electrical rack and pinion.

BENEFITS

One of the main differences between rack-and-pinion steering and other types – mostly recirculating-ball steering – is the direct connection of the components. Recirculating-ball systems transfer steering forces through a series of gears and ball bearings that tend to diminish the feel of the tires on the road. That feel is transmitted better by a steering rack. (Recirculating-ball steering systems are better suited to heavy-duty vehicles, because they can be engineered to bring greater forces to bear for turning the front wheels.)Rack-and-pinion steering also is more precise. A small degree of movement with the steering wheel brings immediate results on the road. Other steering systems tend to have some play in the steering wheel when traveling straight down the road. The rack-and-pinion system has proven more active and fun to drive.Plus, the simpler rack-and-pinion steering systems are easy to service, which contributes to a lower cost of ownership.

                                                       

CARING FOR YOUR STEERING SYSTEM

• Important things to note about steering system care and maintenance:
• ü  When checking fluid levels under the hood, don’t overlook the power steering fluid reservoir. (Check it monthly.)
• ü  Markings on the reservoir indicate maximum and minimum levels for the fluid when hot or cold.
• ü  Do not hold the steering wheel at the fully locked position (left or right) for more than five seconds, because it may damage seals within the system.