We have a Lady Kenmore Heavy Duty series 90 model 9370. Last week it stopped switching cycles. When I start the washer, it fills with water and begins to agitate. But it will continue agitating unless I manually advance the knob. I must continue to do this for each cycle or it will just continue to agitate during wash and rinse cycles. Is there a timer or something that can be replaced to correct this? Thanks I appreciate any assistance. There are 4 of us attempting to use this washer and running out to change cycles every 15 minutes is driving us nuts!