Your Drive Train Explained

The drive train serves two functions: it transmits power from the engine to the drive wheels, and it varies the amount of torque. "Power" is the rate or speed at which work is performed. "Torque" is turning or twisting force. Multiple ratio gearboxes are necessary because the engine delivers its maximum power at certain speeds, or RPM (Rotations Per Minute). In order to use the same engine RPM's at different road speeds, it is necessary to change the "Gear Ratio" between the engine and the drive wheels. Just like a bicycle, the car has to switch gears in order to move at a wide range of speeds. Unlike your bicycle, the car's drivetrain also has to allow you to back up. (Well, you could push it backwards if you ate your Wheaties)

There are actually two sets of gears in the drive train; the transmission and the differential. The transmission allows the gear ratio to be adjusted, and the differential lets the drive wheels turn at different speeds.

Manual transmissions usually have four or five speeds, and often have "overdrive", which means that the output shaft can turn faster than the input shaft for fuel economy on the highway. Some use an electric clutch and a switch that controls whether the overdrive is engaged or not. An interesting development on a few cars is the "clutchless" manual transmission, which uses a stick shift and an automatic electric clutch. Speed and position sensors, mini computers, and throttle controls keep the engine from over-revving when the driver shifts gears. As with many automotive "inventions", this is an old idea, which may now reach feasibility due to the computer revolution.

Automatic transmissions commonly use three forward gears to blend speed and torque. In the case of a three-speed transmission, first gear delivers maximum torque and minimum speed for starting. Second gear offers medium torque and speed for acceleration and hill climbing. Third gear allows maximum speed with minimum torque for highway travel. A reverse gear permits backward movement.

A transmission is a speed and power-changing device installed at some point between the engine and driving wheels of a vehicle. It provides a means for changing the ratio between engine RPM (Revolutions Per Minute) and driving wheel RPM to best meet each particular driving situation.

Some types of drive train layouts use a "Transaxle", which is simply a combination of the transmission and the differential. These are usually found on front wheel drive cars, but are also used on mid- and rear-engine cars. Some exotic cars have their engine in the front, and a transaxle in the rear of the car for better weight balance.

Torque is derived from power. The amount of torque obtainable from a source of power is proportional to the distance from the center of rotation at which it is applied. It is logical, then, that if we have a shaft (in this case, the crankshaft) rotating at any given speed, we can put gears of different sizes on the shaft and obtain different results. If we put a large gear on the shaft, we will get more speed and less power at the rim than with a small gear. If we place another shaft parallel to our driving shaft and install gears on it in line with those on the driving shaft, we can obtain almost any desired combination of speed or power within the limits of the engine's ability. That is exactly what an automobile transmission does by means of gears and other devices.

There are two types of transmissions; manual and automatic. If you have a manual transmission, you have to shift the gears yourself, usually with a stick located on your console and the clutch pedal. If you have an automatic transmission, the mechanism changes without any help from you. This is accomplished through a system that works by oil pressure. Each shift of the gears is controlled by a shift valve; the gears shift change depending on speed, the road, and load conditions.

Another basic component of all drive trains is some form of a clutch. it allows the engine to continue rotating while the gears and wheels are stationary. Automatic transmission cars use a "torque converter" in lieu of a clutch.

The last component in the drive train is the axle. In a rear wheel drive car the axle is in the rear. Engine power is transmitted from the transmission to the axle via the drive shaft. The drive shaft is basically a metal tube with joints on each end called universal joints. These joints allow the tube to move in relation to the suspension and keep power flowing to the rear. In front wheel drive cars the axle is integrated into the transmission thus the term transaxle.

From the back of the engine to where the rubber meets the road, the drive train encompasses one of the most complicated systems of your car. Some people say looking at a transmission "makes their brain hurt".

The above information is directly from the Auto Insight program, which you can buy online from AutoEducation.com.
Common Problems:

· Manual transmissions suffer from wear mainly in the synchronizers. The synchronizers make shifting easier and help to prevent gear clash. Over time the synchronizers, which are made of brass, can wear out causing hard shifting and grinding.
· Automatic transmissions can also wear out, causing slipping and uneven shifting patterns. Universal joints can wear and cause vibrations while driving. Many newer universal joints are sealed and cannot be lubricated, leaving replacement as the only option.

Preventive Maintenance:

· Change the fluid in your transmission at recommended intervals. Your owners manual will give you a time schedule in miles and or months. If you tow a boat or trailer be prepared to change the fluid even sooner. Most owners manuals will give you recommend intervals for severe use like towing or off-road use.
· Do not "ride" the clutch if you have a manual transmission. Learn to release the clutch in a smooth motion without revving the engine too much. Revving the engine too much while pulling out can cause premature wear on the clutch.
· If you do tow a boat or trailer, consider getting a transmission cooler for your automatic transmission. Temperatures can approach the boiling point in severe conditions. Most newer trucks come equipped with transmission coolers if sold with a towing package.
· Make sure your universal joint is lubricated at oil changes if they are the type, which can be lubricated. When replacing universal joints try to find replacements with lubrication fittings so you can lubricate in the future.
· If you have a front wheel drive car, avoid applying the gas to the floor while the wheels are turned at full lock. This puts stress on the universals and can cause premature failure. This can happen when stuck in the snow and trying to get out.

What to discuss with your mechanic:

· If you are noticing a vibration in the car while driving, make sure to describe when it happens. While accelerating? braking? maintaining speed? when turning?

About the author:
Kevin Schappell maintains http://www.carbuyersclub.com where he gives advice on buying, selling, insurance, and financing. A mechanical engineer and car guy, Kevin has decided to spend his online time helping others learn about automobiles. To learn more about how your car works, Kevin has created http://www.mycarwizard.com
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Eleven Money-Saving Auto Insurance Tips for Senior Drivers

Like all drivers, senior citizens (or as I like to call them “seasoned citizens”) want to get the best rates on their auto insurance policies. What they may not be aware of is that older drivers may present a higher risk than other drivers, usually leading to higher auto insurance rates.

Following a few simple tips and taking these measures will ensure that you are getting the lowest rates possible on your auto insurance policy.

1. Avoid more Accidents, Pay Close Attention at Intersections. Auto accidents involving seniors often occur at intersections. Make sure to look ahead if you plan to quickly change lanes after an intersection. Pay attention to protected left turn lanes with their own arrows, and always keep your tires pointed straight ahead when stopped, so that a rear-end accident doesn't push you into oncoming traffic.

2. Follow the flow of traffic, Drive at the at or near the speed limit. Driving too slowly can be just as dangerous as speeding, especially when entering or exiting interstates or freeways. It can also trigger dangerous "road rage" in less patient drivers. You don’t have to be Mario Andretti, but keeping to the right and following the flow of traffic is the safest bet.

3. Many violations include failure to yield right-of-way, improper turning or incorrect lane changes, so keep current on the traffic laws relating to new traffic designs.

4. Sit high enough in your seat so that you can see at least 10 feet in front of your car, advises the National Highway Traffic Safety Administration. If your car seat does not adjust to allow this, add a cushion. This will make it easier to see pedestrians and bike riders, and reduce problems from oncoming headlight glare at night.

5. Do not wear sunglasses or tinted glasses when driving at night. For many older drivers, night vision is reduced, so safety dictates not driving at twilight or after dark.

6. Make sure you learn how to operate a New Car. Things like Anti-lock brakes, for example operate differently in slippery situations. If you have never driven a car with anti-lock brakes, sure to get training on proper use.

7. Senior drivers can refresh their skills and knowledge -- and get a discount on auto insurance in many states -- by taking a refresher driving course, such as the eight-hour "55 Alive" course offered by AARP. More than two-thirds of states mandate auto insurance policy discounts for such courses, and many insurance companies offer the discounts voluntarily.

8. Look for cars with rear-view mirrors that automatically dim and filter out headlight glare.

9. Air bag technology has become more advanced, with sensors that deploy air bags based on the weight of the occupant, reducing air-bag-related injuries. Some new cars also have side air bags in the seats or door frame that offer better protection.

10. Consider fit and comfort in your new car. Seat belts that comfortably fit over your shoulder and low on your lap will keep you safer. Automatic transmission, power steering and power brakes require less physical effort.

11. Last but definitely not least, Check to see which companies offer specific ‘Senior Discounts’ While shopping around for the best auto insurance rates is important, which insurance company you choose might depend on how they treat senior drivers. You'll get their best rates if you're healthy and drive a safe, modern vehicle.

Reprints of this article are allowed (and encouraged) for your site or newsletter with proper credit to the author and a simple link to http://www.hometownquotes.com.

About the Author:
Matt McWilliams is one of the co-founders of HometownQuotes.Com, an online insurance quotes web site. He is originally from Pinebluff, NC and attended Middle Tennessee State University in 2002. He is considered an expert in the field of online insurance shopping and finding new ways to help consumers save money on their insurance. For more information visit http://www.hometownquotes.com.
This article was posted on August 27, 2005
Article Source: articlecity

Driving Safely as You Get Older

Driving a car is a very complex task. You need good perceptual and judgement skills and you must pay constant attention to detail from your car and the world around you. As 90% of the information you need for safe driving comes through your eyes, any drop in vision due to age may compromise your safety. Although vehicle accidents usually have multiple causes, one of the more common causes is YOU, the driver, failing to see something important. Lose visual concentration at the wrong time, even for a second, and you may miss seeing a potential danger that could kill you and your passengers.

Despite nationwide driving fatality numbers decreasing, drivers aged 70 and over are more frequently involved in driving accidents (particularly fatalities) through decreased driving performance. Decreasing vision through ageing and common eye diseases is often a major contributing factor to such cases. With a rapidly ageing population and 19.8 million drivers over 70 already on U.S. roads, declining driver competence is fast becoming an urgent public health problem. One frightening statistic from the National Highway Traffic Safety Administration indicates that older driver involvement in fatal crashes will increase by 155% by the year 2030.

With increasing age many physical and mental changes will affect your ability to drive safely. Some conditions clearly make driving dangerous. If Dementia or Alzheimer's impairs your thinking or serious Cardiovascular disease makes you pass out from time to time, you need to immediately stop driving for your own and others' safety. Other less obvious problems may be just as dangerous at times. You may be temporarily unfit to drive if your prescription medicine makes you drowsy or if you are diabetic and your blood sugar drops too low. Impaired vision is another less obvious problem for older drivers. You may think you can see well, particularly in familiar driving locations, but as vision can deteriorate gradually over time, you may be totally unaware that your vision is not safe to drive!

Driving authorities impose a number of vision standards for safe driving. They may differ slightly from place to place but there are some common requirements. You need good visual acuity. This is the ability to see far enough ahead of you to recognize and avoid potentially dangerous situations. You need good peripheral (side) vision. This is the ability to see out to the sides when changing lanes or merging. It helps you to detect pedestrians and other roadside hazards. Night vision is also important. Poor night vision due to problems like cataract can affect may elderly drivers. They may require a conditional driving license that only allows daytime driving.

Although eye disease such as Cataracts, Glaucoma and Macular Degeneration are relatively common in seniors, they are not the most frequent vision problem affecting drivers. The most common visual impairment in older drivers is uncorrected refractive error. Many drivers are either unaware they need eyeglasses to drive or they fail to keep their prescriptions up to date because they have not noticed the gradual loss of vision.

It is important to make sure eye diseases are monitored regularly to ensure vision remains adequate to drive. Cataract surgery may restore driving vision when cloudy lenses affect your vision but some eye diseases progress to the point where you need to stop driving altogether. As many older drivers equate their driving license with physical independence, losing this ability can be a terrible event which can force major lifestyle changes.

In this fast paced mobile world, driving is almost a necessity for many people. It can be devastating when age and deteriorating vision limit this ability. Although you can't turn back the clock, regular eye examinations and good communication with your Eyecare practitioner can help you keep driving as long as possible. Check your eyes regularly and make sure your eyes stay safe to drive!

About the Author:
Ian Williamson
For More Driving Articles by Ian Williamson please visit http://www.real-articles.com/Category/Cars/145
Submitted: 2006-04-17
Article Source: GoArticles