To understand if this is helping or not, it might help to understand how the transmission does what it does.
The key to the modern automatic transmission is the torque converter. It takes the place of a clutch in a manual transmission.
A direct descendant of an earlier component called a fluid coupling, the torque converter offers the advantage of multiplying the turning power provided by the engine. It is connected to the motor by means of a metal rod known as the transmission shaft (sometimes called the input shaft), which fits next to but does not touch the engine crankshaft. Repeat: there is no direct connection between the engine and the transmission.
Instead, the engine turns the transmission by means of a process called hydraulic coupling.
Think of two electric fans in a room. Line them up a few feet apart, one in front of the other, both facing the same direction. Now turn on the rear fan. What happens? If you've turned the fan up high enough, and if the fans are close enough together, the front fan will begin to turn as well. In this same manner does the engine crankshaft influence the transmission shaft, causing it to rotate.
The identical process occurs in a torque converter, except that transmission fluid takes the place of air.
In this example, move the shifter and watch where power is flowing through the transmission in what gear. You'll notice that in park and in neutral that the power is stopped at the torque converter and does not produce any movement in the clutch area.
Click Here to see what is moving in what gear.
Now this is a simple basic concept but in drive and such, the power is transmitted but only if the rpm's are such that it will cause the torque converter to convert the power to the transmission. Look at how a torque converter produces the power out...
A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight, the amount of torque passed through the torque converter is very small, so keeping the car still requires only a light pressure on the brake pedal.
If you were to step on the gas pedal while the car is stopped, you would have to press harder on the brake to keep the car from moving. This is because when you step on the gas, the engine speeds up and pumps more fluid into the torque converter, causing more torque to be transmitted to the wheels
This is how the parts of the torque converter connect to the transmission and engine
The pump inside a torque converter is a type of centrifugal pump. As it spins, fluid is flung to the outside, much as the spin cycle of a washing machine flings water and clothes to the outside of the wash tub. As fluid is flung to the outside, a vacuum is created that draws more fluid in at the center.
The fluid then enters the blades of the turbine, which is connected to the transmission. The turbine causes the transmission to spin, which basically moves your car.
So, in reality, you do have some pressure engaging the engine to the clutches in a transmission but when you put it in neutral, the idle steps up slightly under a no load condition, then when dropped into gear, it will engage the clutches. So question is, is the wear in gear at idle more detrimental than in neutral then dropping back into gear? IMO, there is more wear produced by shifting back and forth than leaving it in gear all the time because of the dis engagement/engagement process.
