Our Whirlpool Duet washer exhibits a very unique sound when the tub is spinning. The higher the RPM's the louder the noise. The washer is in a work place and the noise is becoming a nuisance (the machine still effectively spins out the water). Before removing the rear panel and investigating, any possible points of interest someone could give me...my suspicion is a bearing at the rear of the tub, or in the motor. Thanks for your help.