Diagnosis
The drum support rollers are worn out. Their rubber surface wears down, then the metal hub grinds against the drum glide.
How to Fix It
Unplug dryer. Remove the top panel and front panel. You'll see the rollers at the rear of the drum, near the bottom. Spin them by hand. A bad roller won't spin smoothly and will feel gritty. Replace both rollers (part DC97-16757A) and the rear felt seal (DC97-00679A) while you're in there.
If That Didn't Work
The noise could be from the idler pulley. It tensions the drive belt. Its bearing fails and squeals. Inspect it for wobble and replace (part DC97-00677A) if needed.
Heads Up
Replace rollers in pairs. If one is worn, the other is close behind. Lubricating them is a temporary fix and can attract more lint.