Sonnax TH400 34555-44A Aluminum Clutch Steel

For use with Sonnax 28-spline forward drums.

Traditional clutch packs use steel separator plates. Sonnax aluminum clutch steel 34555-44A is a lightweight upgrade for GM TH400 transmissions that reduces total clutch pack weight by about 1 lb. for improved efficiency and drivetrain response. This plate is for use with Sonnax 28-spline forward drums, including the Smart-Tech drum module and heavy duty forward drum 34554-01

Each Sonnax aluminum plate weighs approximately 1.6 oz. — 63% lighter than a comparable steel plate. The significant weight reduction decreases forward clutch rotational mass to improve performance. A thin, anodized coating reduces wear and seals the plate surface to prevent oxidation (“smut”) from transferring to the frictions and contaminating fluid.

These plates are recommended for forward clutch applications, where no shift-related heat energy is generated. They can also be used in direct clutch packs if proper care is taken to account for their reduced density and heat absorption compared to conventional steel plates.

• Improves acceleration and rotating efficiency of Sonnax 28-spline forward drums
• 63% Lighter aluminum plates reduce forward clutch pack weight by about 1 lb.
• Anodized plates will not wear or discolor fluid
• A lightweight spacer option behind standard steel plates when reducing forward or direct clutch friction count
• Not compatible with OE-style drums with 14 clutch splines.
• Material: Aluminum
• Tooth Count: 28
• Thickness: 0.080″