Our Whirlpool WTW4800BQ0 washer recently starting making a grinding noise during agitation only. I have replaced the drive dogs but the noise continues. It sounds like plastic gears/teeth grinding. By jumping the lid switch, I observed the machine during the agitation cycle. I gently pressed down on the agitator (fabric softener dispenser) and the noise goes away; however, if I lift slightly the noise will worsen. Any ideas? The noise is only present during the agitating cycle. Thanks.