Washer fills up but won't agitate

Try looking under it as I've had that problem and found it was build up of dust

I had the same problem kinda. Does it start to agitate before it fills with water? Its supposed to fill with water, agitate, sense the amount of the load, then fill with the correct amount of water. If it agitates right away then you need a water level/ temperature control sensor. I replaced mine and no longer have the problem of wet clothes at the end of the cycle. The part number is w10248240. Look on you tube for a video on how to replace. The one I saw showed how to diagnose the sensor. The part cost about $90 and it took longer for me to get out my tools than replacing the part. This part goes bad by starting the machine then adding more clothes after it starts. You can also try blowing air down the tube from the back of the sensor. It didn't work for me but was suggested and blowing the air didn't cost anything.

Heck your warranty--sounds like the cellonoid is sticking

So when the cycle first starts, it will fill and agitate and spin. But then on the rinse cycle it stops?

If it won't fill you will need to replace the "water inlet valve" on the back of the unit. The unit will only agitate if it gets the signal from the water level pressure switch.
Here is the valve to order.

It sounds like the transmission is done. Can't pinpoint what it is exactly, but I would start there.

WASHER FILLS WITH WATER, THEN WON'T AGITATE. TURN KNOB TO SPIN AND IT DRAINS THEN SPINS. STILL WON'T AGITATE please show me a diagram

I have the exact same problem with my Kenmore 800 top loader, Model # 110.29822800. It is only 1.5 years old. Any suggestions?

Normally yes. There are around 12 to 20 gallons of water in the tub after the wash cycle, which will be anywhere from 63 to 110 pounds of weight in addition to the weight of the clothes. For the machine to start the spin cycle to remove this water would place a heavy load on the motor, gearcase, pullys, belts, gears, ect. With the water drained, the load is lighter, and much easier to start spinning the excess water out of the clothes. The normal cycles are: Fill, Agitate, Drain, Spin, Rinse Fill, Agitate for rinse, Drain, Spin Cycle and off. Imagine trying to spin a 5 gallon bucket of water over your head, full of water, and then empty. Which one do you think would be easier to do? And safer for you.

No agitation or spin in any cycle? If so and the machine will drain check the coupler.