ZF 8HP70, 8HP75 & 8HP76 Spool Billet 300M C-Hub Cog Drive

The Spool billet 300M C-hub cog drive replaces the cast steel factory part in ZF 8HP70, 8HP75 and 8HP76 transmissions with a much stronger machined piece.

Why you need it

The factory C-hub cog drive is cast, and casting brings porosity, uneven grain and stress points. As torque, line pressure and shift aggression go up, that shows up as deformed cog teeth, spline wear and cracking under shock load. Spool machines this hub from billet 300M, a vacuum-melted ultra-high-strength alloy steel used in aerospace and motorsport drivelines, for higher strength, better fatigue resistance and consistent properties throughout.

Fits

• ZF 8HP70 transmissions
• ZF 8HP75 transmissions
• ZF 8HP76 transmissions

Features

• Fully CNC-machined from billet 300M alloy steel
• Higher strength and fatigue resistance than cast steel
• Tight tolerances for accurate cog geometry and even load spread
• Cleaner torque transfer and more consistent shifts

Good to know

A key reliability part for any 8HP70, 8HP75 or 8HP76 build with more power, upgraded clutches or higher line pressure. Installation requires a transmission teardown, so professional installation is recommended.