6L80 / 6L90 High Capacity 4-5-6 Clutch Apply Piston Kit, Sonnax 104960-10K.
Due to OE design flaws, GM 6L80 and 6L90 transmissions frequently fail the 4-5-6 clutch assembly. Clutch plate failure is caused by a lack of clutches and a small clutch piston-to-plate surface area, especially when application pressures exceed OE standards. The backing plate (coning) is also prone to flexing and bowing, which is a leading cause of clutch failure.
The Sonnax 104960-10K high-capacity 4-5-6 clutch apply piston kit includes a modified OE clutch apply piston and piston dam, as well as a specifically designed toothed apply plate closest to the piston. The Sonnax toothed apply plate expands the surface area between the apply piston and the first friction plate, resulting in a more even distribution of apply force to clutch plates and the ability to use a friction plate.
- Solid backing plate design outperforms OE and aftermarket plates
- Toothed apply plate eliminates waved plate
- Use with stock clutches and one additional OE-style friction
OEM frictions are about .063″ thick, and OEM steels are about .086″ thick. Utilizing these frictions and steels, this kit allows one additional friction plate to be installed for a total of 7 frictions in a 6L80 and 8 frictions in a 6L90.
- Backing Plate
- Apply Plate
- Piston Dam
- Apply Piston