What Can Overfilling a Transmission Do?

Erratic Shifting: When you overfill your transmission with fluid, the gears become submerged in transmission fluid. These gears will have a difficult time-shifting making it more difficult to drive. ... This can cause wear and tear on your transmission and damage the system in the long run.

What problems can an overfilled transmission cause?

When an automatic transmission is overfilled, the fluid foams, leading to gear shifting problems, oil starvation as well as transmission damage. On the other hand, an overfilled manual transmission results in fluid-leak from the vent and the shifting the gear becomes a problem when the clutch is depressed.

How do you know if your transmission fluid is overfilled?