Sonnax 76656-01K, 4R70E / 4R75E / 4R70W / 4R75W Smart-Tech® Direct Clutch Drum & Shaft Kit

When the listed Ford transmissions are pushed to their limit, the intermediate stub shaft and direct drum will fail. To maximize durability and improve clutch capacity in heavy-duty/performance vehicles, Sonnax offers the Smart-Tech direct clutch drum and shaft kit 76656-01K. The first upgrade to eliminate every critical weakness.

Most failures in these units occur where the direct drum and stub shaft connect. Even other aftermarket upgrades that rely on a heavy-duty shaft will sheer in this area under extreme conditions. Unlike those two-piece assemblies, the all-in-one Smart-Tech easily handles the highest horsepower and torque levels.. The shaft itself is significantly thicker and 2X stronger than the OE.

4R70-series transmissions fall short, but installing thinner aftermarket steels and backing plates to increase clutch capacity isn’t ideal. Those components increase clutch pack flex and heat buildup, making them the primary cause of repeat burn-up. In order to improve both performance and long-term reliability, the Smart-Tech’s custom drum and piston hold an OE backing plate and seven OE frictions for 17% more clutch capacity than the six-friction stack-up.

• One-piece design eliminates weak point where drum splines strip and shafts break
• Rugged shaft is 50% thicker and twice as strong as OE
• Custom drum and piston deliver 17% more clutch capacity with optimum protection against burn-up
• High-strength drum and shaft are precision-machined from hardened 8620 steel