Product review (5 stars): Easy fix!!
This simple kit is what fixed my Whirlpool  dishwasher that is approximately 15 years old!!  Just a tip: you need to order the upper spray arm rack mount #8539324 for this all to attach properly to your dishwasher rack.  I am thankful for the other reviewer that left the same info on their review because I ordered the arm rack mount as they suggested, which costed less than $2 and I was glad I did!! Because I would not have been able to attach the arm kit to my top dish washer rack without it!!