Wheel alignment adjusts the wheel angles so that they are parallel to one another and to the ground. Proper wheel alignment and related maintenance is critical to keeping a vehicle in top condition. Wheel alignment is also important for safety reasons--poor alignment can result in issues regarding uneven tire wear and tracking, as well as create steering problems.
How Wheel Alignments Are Performed
Wheel technicians will test drive your car prior to performing service on it.
Wheel alignment technicians check an automobiles alignment by test driving it prior to servicing it. Test drives provide the technician firsthand knowledge of steering and tire performance, giving him important information that will allow him to effectively diagnose any issues.
Front-Wheel Alignment
A car that pulls to one side while driving may require a front-end alignment.
Front wheel alignment service inspects and adjusts the alignment of the vehicles front tires and axles. A car that regularly pulls to one side or has uneven tire wear indicates the need of a front-wheel alignment, especially when confirmed by a technician. As of 2010, front-end alignment can run approximately $30 to $70, depending on the company and location.
Four-Wheel Alignment
Four-wheel alignment inspects all tires, but technicians may perform it in two different ways. A wheel technician can inspect all four wheels but only service the two front wheels, or he can inspect and service all four wheels, which is known as a full four-wheel alignment. Full alignment services are more expensive than other types of alignment services because of the extensive work. As of 2010, this service can cost between $50 to $100 depending on the company and its location.
The performance difference in single and dual-exhaust systems is solely based on the amount of evacuation produced. Although two pipes can evacuate more exhaust, a single exhaust system with larger evacuation pipes provides the same performance.
General Information
Each cylinder in the engine has a pipe extending from it for exhaust. All pipes are joined into one pipe as an exit point that connects to the systems head pipe. The head pipe joins with the catalytic converter, which converts toxic fumes to reusable air. The catalytic converter then sends the exhaust through the muffler, which acts as a second filter, sending the remaining air through the tail pipe.
Single Exhaust
Single exhaust systems have one catalytic converter, one muffler and one exhaust pipe. They cannot be converted into true dual exhaust systems because smog regulations do not allow catalytic converter changes. When properly configured, a single exhaust system is just as productive as a dual.
Dual Exhaust
Dual exhaust systems are either true-dual or split-dual systems. The true-dual exhaust includes two catalytic converters, two mufflers and two exhaust pipes. The split-dual system has one catalytic converter, one muffler and two exhaust pipes. According to Flow Master Mufflers, dual exhaust systems increase engine power, use gas more efficiently and reduce engine noise.
The two Toyota engines, 4A-FE and 7A-FE, have many similarities, and yet they are distinct in several ways. They were both used in Corolla model cars. However, there are some notable differences between the two engines. If you are an automotive mechanic who specializes in Toyota repair, familiarize yourself with the differences between these two engines.
Displacement
The 4A-FE has a displacement of 1.6 liters, while the 7A-FE has a displacement of 1.8 liters. The larger displacement of the 7A-FE gives it more horsepower and torque, which generally results in better engine performance.
Horsepower
Horsepower is a measure of how much power an engine produces and is analogous to the SI unit watt. One horsepower is roughly equivalent to 745 watts. Horsepower is achieved by combusting fuel in pistons and spinning a crank shaft. The more fuel supplied to the engine, the faster the crank shaft spins. The rate at which the crank shaft spins is measured in rotations per minute (RPM). The horsepower of a 4A-FE has a range of 103 to 105, with 105 achieved at an engine RPM of 5,800. The 7A-FE has a horsepower of 115 at an RPM of 5,600.
Torque
Torque is a measure of angular force and uses the SI unit newton-meter. However, automobiles often use the non-SI unit foot-pounds. In relation to automobile engines, torque primarily affects acceleration and towing capacity. The 4A-FE has a torque of 100 to 102 foot-pounds at an RPM of 4,800. The 7A-FE has a torque of 115 foot-pounds at an RPM of 2,800.
Head Gasket, Oil Pan and Crankshaft
The 7A-FE uses a different head gasket than the 4A-FE. The gasket is composed of two layers of metal. The oil pan is also different on the 7A-FE. It is made of two separate pieces, one composed of aluminum and one composed of steel. The 7A-FE has a modified crankshaft that matches the higher power output of the 7A-FE engine.
Hydraulic oil and pneumatic (lubricating) oil are two different fluids for entirely different applications. It is important to understand these differences when selecting an oil to use. Choosing the wrong fluid could result in equipment failure or injury.
Hydraulic and Pneumatic
Hydraulic systems use a liquid, such as oil, under pressure to power cylinders, valves, motors and so on. Pneumatic systems use a gas, such as air, under pressure, to power cylinders, valves, motors, among other equipment.
Hyrdaulic Oil
Hydraulic oil, sometimes called hydraulic fluid, is used to transfer energy from one component to another in a hydraulic system. There are several types of oil that may be used in a hydraulic system depending on the individual application. Different oils have varying viscosity and compressibility. The machinery being used typically specifies which type of hydraulic oil is required.
Pneumatic Oil
A pneumatic system is powered by compressed air.
Pneumatic oil, more frequently called lubricating oil, is used to lubricate the moving parts in a pneumatic system. Pneumatic oil typically has a low viscosity and is easily atomized so it can be transported by the compressed air in the system. Some systems will have an oil reservoir that automatically dispenses lubricating pneumatic oil, while others require the operator to manually add a few drops of oil every so often.
Vehicles come with one of two types of transmissions, manual or automatic. With a manual transmission, the driver has to switch gears using the clutch and a gear shift. Automatic transmissions are ideal for drivers who want the vehicle to do the shifting for them.
How Automatic Transmissions Work
When a car with automatic transmission accelerates, the vehicle will monitor when it needs to shift to a higher gear and will do it automatically. Nothing at all is required of the driver. The car starts in first gear and shifts to a higher gear as the vehicle travels faster.
3-Speed Versus 5-Speed
A car with a 3-speed transmission only has three levels of gears. A 5-speed has two more gears than a 3-speed. On many vehicles with five gears, the fifth gear allows the engine to run slower at highway speeds, saving on fuel consumption.
Differences Between 3 and 5 Speed Automatics
One advantage of the 5-speed over the 3-speed automatic is that the higher gears allow you to obtain a higher speed at a lower rpm. Another advantage is that the more gears a car has, the better it will perform regarding acceleration, fuel economy and stress on the engine, in general.
