Diagnosis
Yeah, this one's common. An unbalanced load is the first culprit, but with this model, a worn-out spider arm—the part that connects the inner tub to the drive shaft—can cause serious vibration and noise.
How to Fix It
First, stop and redistribute the load evenly in the tub. Don't wash a single heavy item like a blanket or rug by itself; balance it with a few other things. Run the spin cycle again. If the noise is gone, it was just load balance.
If That Didn't Work
If the grinding/thumping persists with balanced loads, the spider arm is likely corroded or cracked. It's a major repair requiring a full tub disassembly, not a DIY job for most.
Heads Up
Ignoring a bad spider arm can destroy the tub bearings and the entire transmission. If balancing the load doesn't fix it, get it checked out pronto.