Gearstar Launches New 4L80/TH400 Billet Direct Drum with 36‑Element Sprag and OEM‑Size 4L80E Frictions

Gearstar Performance Transmissions is proud to introduce its new 4L80/TH400 Billet Direct Drum, engineered to deliver exceptional strength, durability, and torque‑holding capability for high‑horsepower applications.

Built from premium billet material, the new drum features a 36‑element sprag, high‑capacity friction stack, and—most importantly—full‑size factory 4L80E frictions. Unlike competing drums that rely on smaller Powerglide frictions, Gearstar’s design maintains the larger OEM friction footprint, providing increased surface area, improved heat management, and longer service life under extreme load.

This upgraded drum is a direct fit for both 4L80E and TH400 platforms, making it ideal for drag racing, heavy‑duty performance, and high‑torque street builds.

“With this drum, we focused on eliminating the compromises found in other aftermarket options,” said the Gearstar engineering team. “Using true 4L80E frictions was essential for maximizing durability and power capacity.”

Gearstar’s new billet direct drum is available now through Gearstar and authorized distributors.