This is unusual but not unheard of.

Today's washers generate agitation by means of an oil filled transmission. The transmission output shaft is coupled to the clothes agitator. The drive motor reverses between agitate and spin. (Exceptions are Whirlpool belt-driven, Westinghouse, Bendix and Dexter front loaders and very old Speed Queen. Look out for two solenoids.)

Check for the following:

1. Clothes blocking the agitator. (GE in particular.)

2. Failure in the coupling between the transmission output shaft and the agitator. (Whirlpool and GE particularly.)

3. Failure within the transmission. (very rare)

4. Failure in the timer. (The motor reversal contacts have failed. Also rare.)

For further information or brand-specific information, please consult the appropriate Manual.