Which of the following could cause failure of an automatic transmission?

• A. Low fluid pressure
• B. High fluid level
• C. Low fluid level
• D. All of the choices are correct.

Answer: (D)

Automatic transmissions rely on hydraulic pressure from circulating fluid to engage gears. If the fluid pressure is too low, the clutches and bands can’t hold properly, causing slipping, overheating, and accelerated wear. A low fluid level does the same thing—insufficient fluid to pressurize and cool the internal components leads to poor operation and potential failure. If the fluid level is too high, the fluid can become aerated and foamy, reducing lubrication and proper pressure, which can cause erratic shifting and additional stress on seals and components. Since any of these situations disrupts the hydraulic system the transmission depends on, all of these conditions could lead to transmission failure.