Spool Performance 8HP70 / 8HP75 / 8HP76 upgraded billet 7075-T6 D Clutch Drum

Spool Performance 8HP70 / 8HP75 / 8HP76 upgraded billet 7075-T6 D Clutch Drum

The Spool billet D-clutch drum replaces the factory A380 cast-aluminium drum in the 8HP70, 8HP75 and 8HP76. The stock casting can crack, distort or suffer from poor oil control at high torque. The replacement is CNC-machined from solid 7075-T6 billet with no casting porosity or inconsistent grain structure.

Why 7075-T6?

• Far greater strength and fatigue resistance than A380 cast aluminium
• Hard anodising protects the clutch-tooth contact surfaces
• Lower rotating mass than a steel drum
• Accurate machining improves roundness, wall consistency and clutch-apply stability
• Revised oil passages improve lubrication, cooling and evacuation

This is a sensible reliability upgrade for a built 8HP running increased line pressure, upgraded clutches and substantially more torque than stock. Installation is part of a professional transmission build.