The neutral drain in the Whirlpool direct-drive washer puts the transmission into neutral while the tub is draining. The purpose is to save wear and tear on the clutch, drive coupler, and motor. While it's function and operation are simple and easy to understand, it can still be confusing for folks.
Chief Master Appliantologist DADoESTX offers one of the simplest and clearest explanations of the neutral drain function that I've ever read:
Neutral drain is exactly that ... no agitation and no spin ... just the motor running to pump out the water.
The motor is reversible. Runs one direction for agitation, reverses for drain and spin.
The pump runs at all times, in whichever direction the motor is running. Agitate direction, it forces the water back into the tub outlet. Reverse (drain & spin) direction, the water pumps out of the tub and through the drain hose.
During agitation, the neutral drain mechanism (cams and pawls and latches and such) in the transmission presets so that when the motor next pauses briefly and restarts in the reverse direction, the tranny goes into neutral drain mode.
When drain is finished (one increment on the timer, 2 minutes), the motor pauses, the neutral drain latch mechanically releases, and the motor restarts in the same (reverse) direction to engage spin. Of course, draining also occurs to pump away the water extracted from the clothes.
The pause between agitate and drain is required both for the motor to coast to a stop before reversing, and for the neutral drain latch to engage.
The pause between drain and spin is required for the neutral drain latch to release.
The neutral drain parts in the transmission wear over time such that it may not preset during agitation, causing spin to begin immediately when the motor reverses.
Very early direct-drive machines (the first couple/three years) did not have the neutral drain feature. There was a pause between agitate and drain for the motor to coast to a stop, but spin (intentionally) started immediately upon the motor's reverse.
Source: Whirlpool WTW5505SQ1