whirlpool cabrio wtw6400sw2 skips rinse cycle doesn't spin fast in wash cycle

In the wash cycle, the washer skips from the washing cycle with 40 min left skips the rinse cycle to go to the spin cycle showing 4 min. spins but not fast leaving the clothes wet. Previously got an oL code.
ihave seen previous threads stating it may be a dirty tub shaft. Why would that cause the machine to skip the rinse cycle? Please help!!