A question that some of us ask ourselves. Or have even been asked by friends or customers. I have a car with a CVT transmission and I have always wondered how a CVT actually worked. I knew it was belt driven but I didn’t know how the belt was driven and how one belt could do the work making it go through “gears”. Now that CVT transmissions are more main stream that they once were most of us have ridden in a car with a CVT.
The number one thing we notice first is that there is not Shift/Step feeling as it switches gears. CVT Transmissions are made to give the engine efficiency under acceleration and going up hills. They also give you improved gas mileage and over the years the benefits are starting too finally out way the cons of owning one. CVT transmissions were not always the most reliable when they first started being introduced to cars but we will get into that later.
CVT Transmissions have 3 main components. There is a Drive pulley, Driven pulley, and a belt. The belts are known to be either high strength rubber or metal. The two pulleys also have clutches and sheathes on them that will move one side of the pulley to make it wider or narrower depdnding on the ratio the cars transmission computer decides it needs to be in. By doing this you have an almost infinite number of ratios. When this happens the other pulley will do the opposite to change the ratio of how much output needs to make it to the wheels. Because of this you do not get any kind “shift” or “Stepping feelings”. The drive pulley is connected to the cars crankshaft. The driven pulley is called so because the drive pulley is turning it. That is known as the output pulley and the cars driveshaft is connected to that.
As you can see in the picture it is a pretty simple concept considering that of a normal automatic transmission that is a nightmare to even look at the inside of. There are multiple types of CVT transmissions but the main one we are going over today is the belt driven type.
The advantages of owning a CVT transmission are tremendous! I have to say I love my car and the loss of “Shift shock” and I always have power whenever I need it. No need to wait for the transmission to shift and get that power. You will also have improved fuel efficiency, there is always better control over emissions and the ride is exceptionally smooth. Some cons of owning one can be the expense of have to replace it and earlier CVT transmissions were not the most reliable. Although they are getting much better throughout the years some people have sworn off of them because of past reliability issues. Also the weak point of these transmissions is the belt. The quality of the belts has been questionable throughout the years. Some last forever and some break within 70K miles, I wouldn’t worry about it though because most manufacturers give a decent warranty on power train.
Finally I have a bonus question for you. What was the first u.s. production car to have a CVT transmission?