What is a sign of low transmission fluid?

A sign of low transmission fluid is difficulty in shifting gears. Transmission fluid is essential for lubricating the internal components of the transmission and for facilitating smooth gear engagement. When the fluid level is low, it can cause increased friction, leading to problems with shifting smoothly between gears. Drivers may experience hesitation, grinding, or a complete inability to change gears properly, which are clear indicators of low fluid levels.

The other options present scenarios that do not directly correlate with low transmission fluid. Increased engine power does not typically relate to fluid levels in the transmission; rough braking usually pertains to issues with the braking system rather than the transmission; and smoother gear transitions would actually suggest adequate transmission fluid levels, as proper lubrication leads to seamless gear changes. Therefore, a difficulty in shifting gears is a clear and direct indication of low transmission fluid.