DIAGNOSIS The spider arm attaching the drum to the rear bearing has cracked. The unbalanced drum grinds against the tub. The smell is plastic/metal overheating.
FIX This is a major repair. You must replace the entire inner tub assembly (part number DD97-00657A). The washer is not safe to run. Unplug it.
IF THAT DIDN'T WORK Not applicable. A cracked spider arm is definitive. If noise persists after tub replacement, the rear bearing and seal kit (DC97-15413A) was also damaged and needs replacement.
HEADS UP Continuing to run it risks the drum detaching completely. This can destroy the outer tub and is a safety hazard.