Checking your transmission fluid involves parking your vehicle on a level surface, applying the parking brake, and then running the engine. With the engine running, you can pull out the transmission fluid dipstick, wipe it clean, reinsert it, then pull it out again to check the level. It's essential to note that the process may vary based on your vehicle's make and model, and some newer vehicles do not have a dipstick. If you're unsure, we at Grease Pro would be happy to help you check it.