ATI’s Lightweight Steel Clutch Drum Assembly For Powerglides

For Powerglide racers, every fraction of a second counts, and so does every ounce of rotating weight. Automatic Transmissions, Inc. (ATI) Performance Products just introduced a new part that targets both with its lightweight steel clutch drum assembly. This new drum (P/N 205648) isn’t a simple copy; it’s a re-engineered piece designed to make the transmission accelerate faster and, more importantly, last longer.

The new drum, complete with its eight-clutch pack, weighs only 8.6 pounds. That’s almost a full pound lighter than a stock drum or a standard aftermarket replacement. A pound might not seem like much, but when it’s part of the rotating assembly, it’s a huge deal. Less mass means the engine can spin the drum up faster, translating directly into quicker acceleration and a better elapsed time.

But the real action happens during that notoriously violent one-two shift. In a Powerglide, the high gear drum has to accelerate from a near-standstill to full engine rpm almost instantly. All the inertia from a heavy stock drum just hammers the clutches, generating excessive heat and causing accelerated wear. By shaving off that extra weight, the ATI lightweight steel clutch drum assembly dramatically reduces that brutal impact, leading to cleaner shifts and a much happier, longer-lasting clutch pack. That’s a critical advantage for any racer who relies on consistency round after round.

ATI didn’t just make it light; they also engineered it for strength, adding increased surface area for enhanced durability. This isn’t a bare-bones part, either. It’s a complete, “ready-to-install” assembly right out of the box. It comes fully loaded with the eight clutches, steel, a new piston, springs, a retainer, a snap ring, and a 19-spline clutch hub.

This new ATI lightweight steel clutch drum assembly is a smart solution for one of the Powerglide’s weakest points. It shaves weight to improve performance while simultaneously adding durability by taking the shock load off the high gear clutches. For serious racers, this is a well-thought-out upgrade that addresses speed and reliability in one shot.