Tamiya 84425 - Aluminium Lower Gearbox for TB Series  [84425]

Solid Aluminium Lower Gearbox for TB Models

The Tamiya 84425 Aluminium Lower Gearbox replaces the stock plastic lower shell on TB-03, TB-04 and TB Evo.6 chassis, improving drivetrain efficiency and overall structural stiffness. It gives a firmer mounting surface for suspension parts and upper mounts while remaining straightforward to fit.

Why Choose an Aluminium Bottom Case

An aluminium lower case reduces flex and offers a durable surface for damper stays and upper mount points. Its machined construction resists wear and maintains better alignment under hard driving conditions.

Fitment and Use Cases

Compatible with both front and rear positions on the specified TB chassis, this part is suitable for track builds and aggressive club use. It helps keep drivetrain alignment stable for consistent handling lap after lap.