For ’85-later units with 298mm converter, 30-spline input shaft. For ’82–’84 units with 27-spline input shaft, converter and stator shaft will need to be updated to ’85-later design.

Input shaft failure is a common problem in GM 4L60 and 4L60-E units as power levels are increased. Sonnax heavy duty input shaft 77733-10SB for 298mm torque converter units is ideal for any high-horsepower street or strip application. The shaft is manufactured from 300M ultra high-strength steel for exceptional toughness and resistance to fracture. It features a revised turbine end spline without an undercut where OE shafts commonly break.

• High-strength 300M steel shaft is more than 2X stronger than OE
• Shot peened for extreme durability
• Unique design protects against failure from stress cracks