Top-load Whirlpool washer agitator does not move or only the bottom moves while the top is loose.

Safety first: Unplug the washer before working inside the tub.

Step-by-step:

• Remove agitator cap: Pry off the fabric softener dispenser or cap on top of the agitator.
• Remove bolt: Use a socket to remove the agitator retaining bolt.
• Lift agitator: Pull the agitator straight up. You may need to rock it gently.
• Replace dogs: Separate the upper agitator from the lower and replace the plastic agitator dogs with new Whirlpool parts.
• Reassemble: Reinstall the agitator, tighten the bolt, and replace the cap.

When to call a technician: This is generally a DIY-friendly repair; professional help is rarely needed unless parts are seized or damaged.