DIAGNOSIS A severe grinding or scraping noise during spin points to the spider arm — the central component that holds the drum — being cracked or broken. On LG top loaders with the direct drive motor, this is a known failure point, especially if the unit is older or has seen heavy use.
FIX Stop using it immediately. Continuing can cause catastrophic damage. You need to verify the spider arm. This requires disassembling the washer: unplug, drain water, remove the agitator and inner basket. Inspect the large, three-legged spider arm attached to the outer tub for cracks or breaks. If damaged, the entire outer tub assembly (which includes the spider arm) must be replaced. This is a major, expensive repair.
IF THAT DIDN'T WORK If the spider arm looks intact, the noise could be a foreign object (like a bra underwire or coin) caught between the inner basket and outer tub. Tilt the washer back and check the gap visually or by feel.
HEADS UP This is not a DIY fix for most people. The parts are heavy and the repair is complex. Getting a quote from a technician versus the cost/value of the washer is your next step.