In a traditional automatic transmission, the gears are literally gears — interlocking, toothed wheels that help transmit and modify rotary motion and torque. A combination of planetary gears creates all of the different gear ratios that the transmission can produce, typically four forward gears and one reverse gear. When this type of transmission cycles through its gears, the driver can feel jolts as each gear is engaged.
Simply put, the theory of operation and parts used in a traditional transmission are all similar and perform similar duties, even if you can’t interchange the parts.
Meaning they operate off of fluid pressure from the front pump. The pressure flows through the proper circuits inside the transmission, directed by the brain or valve body. There are many inputs that can help the transmission make decisions based on how new your car is. Computerized transmissions have a TCM and more inputs than non computerized transmissions. However the basic theory is the same.
The T-700R4 and 4L60-E Chevrolet transmissions are perfect examples of non-computerized and computerized transmissions, respectively speaking, that in essence operate very similarly, except the 4L60-E has a TCM and computer inputs for a more technological shift setup. The guts remain primarily the same, with many parts being interchangeable.
An example of a non conventional transmission is a CVT unit. Becoming more popular nowadays, although they were introduced to cars in about 1987 in the Subaru brand. Not particularly successful at the time. Research tells us at GotTransmissions.com blog that CVT transmissions are coming into vogue again.
Read more about CVT transmissions in Part-1 and Part-2 on our CVT series. Enjoy.
