Car Maintenance: Flushing Automatic Transmission

What is the difference between a manual and an automatic transmission?
The manual transmission locks and unlocks different sets of gears to the
output shaft to achieve the various gear ratios and so a wide range of
speed. The automatic transmission also does the same job by allowing the
engine to operate in its narrow range of speeds while providing a wide
range of output speeds. But unlike in a manual transmission, in an
automatic transmission, all of the different gear ratios are produced by
the same set of gears.

The center of attention in an automatic transmission is the planetary
gearset which makes it possible to create the different gear ratios that the
transmission can produce. It is about the size of a cantaloupe. Whatever
else is there in transmission are there to help the planetary gearset do
its very important job. It is also known as torque converter.

The torque converter does not require any regular maintenance or
adjustments. However, it produces a tremendous amount of heat which
turns out to be the enemy of transmission fluid. Your car manufacturer
may recommend to change the fluid at regular intervals. It is possible to
change the transmission fluid through draining but even after that much
of the fluid may still remain inside.

That is why flushing the automatic transmission system is often
recommended by service centers as a routine maintenance item. But most
manufacturers nowadays say it's not needed until at least 60,000 miles.
Also do not forget the filter in your transmission. If you have one in your
car, check the owner's manual for when it should be replaced.