Product review (5 stars): 78432700) was squeaking pretty badly. Did a little research and it appeared ...
Our 8 year old Kenmore 400 Series Dryer (Model 110.78432700) was squeaking pretty badly.  Did a little research and it appeared the idler pulley in these dryers are the main problem.  I decided if I was going to open up the machine I might as well use this full kit and replace the idler pulley, drum rollers, and belt all at the same time.  I had cleaned out the interior of the dryer before when replacing the gas coils went bad a few years ago, but the machine had a quarter inch of lint inside (huge fire risk).  Completely vacuumed/cleaned the interior/exterior and replaced the drum rollers, belt, and idler pulley.  The hardest part was getting the retaining clips for the roller bearings on.  Just be patient, and use a screwdriver to expand them so they will slide over the retaining slots.

Overall, a great price on factory replacement parts, and hopefully I get another good 8 years out of the dryer.