Tranny Tubes: [updated]

In older vehicles, the exterior of the tube can rust through. This creates "pinhole" leaks. While fluid doesn't under high pressure in the tube, it can splash out during operation, leading to a low fluid condition. 2. Seal Failure

Housing the dipstick, which indicates whether the fluid level is safe, low, or overfilled. tranny tubes

Providing a port to pour in fresh ATF (Automatic Transmission Fluid). In older vehicles, the exterior of the tube can rust through