Thank you for your question and I understand your concern. I must assume when you say the agitation is very slow that your looking at lower portion of the agitator and not just the upper auger portion.
I added some theory of operation below.
Your washer is not just a typical washer with a typical drive motor or drive system. It uses a mode shifter and an inverter motor. The motor has to sense the load and engage the drive, which takes 20-30 seconds after the tub has filled with water. Throw in an article of clothing, let it run for a minute and then open the lid. You should see the article has moved around if the washer is agitating correctly.
When you hear the mode shifter engage and disengage you will hear a "clicking" sound and assume it's broken. This sound is normal and occurs when the washer goes in and out of agitate and spin. You will hear this multiple times throughout the wash cycle.
The mode shifter is controlled by the motor inverter circuit. When the washer starts the agitation cycle, the inverter energizes the mode shifter coil. The magnetic field of the coil lifts the mode shifter cam, disengaging it from the drive pulley. Without the cam engaged, the drive pulley rotates only the agitator shaft. At the beginning of the agitation cycle, the inverter energizes the mode shifter coil with 135 VDC (PWM) for approximately 18 seconds. This high voltage pulls the mode shifter cam up from the drive pulley. During this time, the motor also rotates clockwise and counterclockwise in short strokes to ensure the mode shifter cam has been released from the drive pulley. This operation is called the Mode Shifter Agitate Program. It is normal to hear metal-to-metal "clunking" sounds during this time as the cam and drive pulley disengage. The washer runs this program when the agitation cycle first starts, when power is restored if lost during agitation or when the user restarts the washer if paused. Once the Mode Shifter Agitate Program has completed (18 seconds), agitation begins. During agitation, the inverter continues to supply 30 VDC (PWM) to the mode shifter coil. This voltage is sufficient to hold the mode shifter cam away from the drive pulley throughout the remainder of the agitation cycle.
The inverter motor controls the speed of agitation
. The agitator stroke rate is approximately 30 strokes per minute. This rate is the same for all cycles. The speed of the motor controls the arc. At fast speed, the arc is approximately 360 degrees. At slower speeds, the arc is substantially less. It is the distance of the arc that determines normal or gentle wash cycles.
If you believe your washer is not agitating normally after the information I provided, then you can have it repaired by a Sears technician. Here is a link that will provide the nearest drop-off locations:
Sears Home Services