We have a Whirlpool Duet dryer that started squealing a few weeks ago. I replaced all four drum rollers, the belt, and the pulley, which fixed our issue for awhile. Now the drum is having trouble turning again. I just pulled it apart again, and none of the drum rollers turned easily. I lubricated them with WD-40 till they were spinning freely. I reassembled, and it seems to have the same issue--the drum seems bound up somehow.

Is there something else I'm missing?

Thanks!
David