Transmission slipping is a situation where the automatic transmission in a vehicle does not shift and engage the gears correctly, causing the engine speed and transmission speed to not correlate. It can be compared to a slipping clutch in a manual transmission. There are several ways you can tell if your transmission is slipping, such as high RPMs, inability to reverse, strange smells, odd noises, and delayed acceleration when pressing the gas. The most common causes of transmission slipping include normal wear and tear, burnt transmission fluid, fluid leaks, clutch problems, and worn or broken bands.If you suspect that your transmission is slipping, it is best to start by checking the fluid level and condition is also important to note that transmission slipping can be a signal that your vehicle needs thorough maintenance, and leaving your transmission unchecked can be risky.