I have a model 110 and the agitator seems to be

This problem is commonly caused by worn agitator dogs on the agitator cam assembly. This is a very simple and inexpensive repair. The upper part of the agitator (called the "auger") has a cam assembly under it that acts as a clutching mechanism to drive it with the rest of the agitator. These cam parts wear out and require replacement from time to time. The following link explains what the dogs are and how to replace them:

http://www.fixya.com/support/r823955-replacing_agitator_dogs

The part number is included in the link provided. You can purchase replacements at appliancepartspros.com for about $5. For a little more you can purchase the entire cam replacement kit, which includes the cam, the thrust bearing, and the dogs for about $11.

NOTE: You can refer to the excellent exploded view parts diagrams the web site has to offer for assistance. The model number is not "110". This is the manufacturer's code. This is the prefix to your model number that identifies the manufacturer of your washer as Whirlpool. You will need the rest of the your model number (located on a nameplate around the wash tub opening) in order to search for parts.

If you have any questions about this repair, please let me know. I hope this helps you.