Sunday, September 4, 2011

A Look at the Typical Rear Wheel Drive Power Transmission Configuration

If you're someone who tends to work on their own vehicles when problems come up you're likely already familiar with this information but for those of us who've typically had a mechanic work on our vehicles this could be some new information. Today we'll take a look at the ways in which most vehicles on the road typically get the power produced by the engine, transferred to the wheels and into the forward motion we all use to get us from point A to point B on a daily basis.

If you think about how a car is configured you have the engine mounted in the front -except on some more exotic or unusual models- and either the front or rear wheels are powered by the engine and propel the car. There are All Wheel Drive models but this is a little more unusual and certainly was not a common variant until recently.

For our first example take a rear wheel drive vehicle: the engine is in the front and the powered wheels in the rear. The power doesn't magically flow from front to back so how is it transferred? Usually you will find a automatic or manual transmission mounted behind the engine. The transmission allows you or the car's automatic system to select the best gear ratio for the current road conditions and load. The engine can work more effectively under heavy load when in a low gear whereas to move at maximum speed you would want a gear that minimizes engine revolutions-per-minute- while maximizing wheel speed.

In rear wheel drive models a drive shaft is attached to the rear of the transmission -typically this attachment point is roughly under the center console- and runs back to the final drive on the rear axle which apportions power between the two rear wheels. Since the drive shaft needs to have some flexibility to move up and down as the suspension compresses and extends over rough roads there are normally a couple joints at certain points in the drive line. These are usually U joints which are a bit different and often longer lasting than the CV joints you will find in the drive systems of front wheel drive cars. U-joints are probably a bit easier than the typical CV joint replacement as well.

If you are curious to find out exactly how this system looks one of the simplest and easiest ways to get a visual picture of it is to find an older truck like a 80s or 90s model Chevy pickup truck. These types are usually tall enough that you can easily take a peak underneath and see the drive shaft attachment points at the transmission end and the rear differential.

Ready to learn more about vehicle drive-line systems and the typical CV joint replacement cost? If so you can read more about CV joints and how they work right here.


View the original article here