The 661570V is a dryer drum drive belt used on many Whirlpool-family 27" dryers. The belt wraps around the drum, routes through the idler pulley/tensioner, and drives off the motor pulley to rotate the drum at operating speed. It’s typically a multi-rib belt designed to maintain traction under heat and load while resisting stretch. Common failures are belt glazing, cracking, rib separation, fraying, or complete breakage—often accelerated by seized drum rollers, a worn idler pulley, a grooved motor pulley, or excessive lint/heat from restricted venting. Symptoms: dryer runs but drum doesn’t turn, burning rubber smell, squealing (idler/rollers), thumping (rollers), or intermittent tumbling. IMPORTANT: Replace the belt and inspect/replace the idler and drum rollers at the same time if there’s any noise or resistance. CRITICAL: Disconnect power before servicing; sharp cabinet edges are common.