GM 6L90 (Captive Clutch) torque converters are a nuisance to rebuild. In these converters, the piston is held onto the cover by leaf springs and rivets that are difficult to remove to get to the clutch plate that is captive between the piston and the cover. Sonnax JMDY performance converter kit GM-RK-24 does not use a captive clutch plate design, making it simple to rebuild these units while improving reliability.

One example of a 6L90 captive clutch unit is the high-horsepower GM Cadillac CTS-V. Its engine can quickly push the stock, two-disc converter clutch past capacity. Sonnax GM-RK-24 is a dampered, 300mm multi-plate upgrade that employs a forged six-pad cover, forged piston and three woven carbon friction elements for significantly increased clutch capacity and durability. By reusing the OE damper with the Sonnax clutch plates (bonded with OE woven carbon friction material), GM-RK-24 ensures optimal TCC apply and release characteristics, as well as slip rates that match OE continuous slip calibrations. Drivability is excellent. This easy-to-build and cost-effective kit includes clear, concise instructions.

While testing this kit, Sonnax found that the pressure needed to keep this multi-plate TCC slipping at the calibrated rate was much less than the pressure needed in a comparable single-disc converter. Because the Sonnax multi-plate clutch needs less pressure, there is less demand placed on transmission electronics and hydraulics. With the GM-RK-24, it’s easy for the transmission to keep the TCC slip within required slip parameters.

Enhanced design features include:

• OE friction material bonded to each clutch plate
• Forged components assure rigid apply and reaction surfaces
• Lathe turned feature on mount pads identifies this kit as a multi-plate
• Added clutch capacity reduces required lockup pressure
• Lower operating pressure reduces demand on transmission electronics and hydraulics