Billet Alm Trans Brake GM TH400

The Billet Alm Trans Brake GM TH400 from Transmission Specialties is a precision-engineered transbrake designed for high-performance drag racing and competitive transmission applications. This component serves racers and enthusiasts who demand repeatable, controlled engine braking and launch control in vehicles equipped with General Motors TH400 three-speed automatic transmissions. The transbrake enables drivers to hold engine RPM at a set point while the transmission is mechanically locked, then release smoothly for consistent 60-foot times and launch performance—a critical advantage in bracket racing where reaction time and consistency determine wins.

Manufactured from billet aluminum for maximum strength and minimal weight, the Billet Alm Trans Brake GM TH400 utilizes precision CNC machining to ensure tight tolerances and reliable engagement under extreme conditions. The billet construction resists cracking and deformation that can occur in cast iron designs during repeated full-throttle launches, while the aluminum material keeps rotating mass low—reducing inertial losses and improving overall driveline response. Internal passages and valve geometry are optimized to modulate fluid flow precisely, allowing the transmission to remain fully locked while under load, then release with hydraulic control for smooth acceleration off the line without shock loading or drivetrain damage.

Dedicated bracket racers, street-legal drag cars, and high-horsepower street machines built around the TH400 platform benefit most from this transbrake, particularly in vehicles where launching consistency and repeatability are non-negotiable. Installation requires integration with the transmission's internal valve body and compatibility with a solenoid-operated control system; professional transmission builders typically handle the full assembly. At 5.8 pounds and compact dimensions (12.3 x 4.7 x 12.4 inches), the unit adds minimal footprint to the transmission case while delivering the launch authority that separates competitive racers from the rest of the field.