Product review (4 stars): Before you push the dishwasher back in!
When the wheels turn it makes extreme noise since the hollow dishwasher door amplifies the sound. Make sure you tighten the wheels enough so they do not turn BEFORE you push the dishwasher back in. Also rub a soap bar all over the nylon string. I read that  lithium grease spray was a great lubricant for this too but have not tried it. I did try WD40 and it made the noise worse.