Over the years, automatic transmissions have been gaining gears but losing dipsticks. Current models reach as high as nine speeds, and a dipstick for checking the transmission fluid has become rare.

Automatic transmission cars should change transmission ... This can be done by looking at the dipstick, located near the firewall under the car's hood. Wipe it clean, re-insert it, and then ...

To add extra transmission fluid, you can simply use a funnel while the dipstick is removed. If the fluid is dirty or gritty, though, adding more could simply dilute the problem.