Sonnax servo piston kit 28821-02K for GM Powerglide units features dual 18608T PTFE seal rings. These rings are configured to be interchangeable with the OE cast aluminum seal ring for maximum flexibility. The piston can be assembled using only one seal ring for lower friction, two aluminum seal rings or any combination in between. Sonnax also offers servo piston kit 28821-01K with dual O-rings 28821-OR for use with worn cases.
Contact a Sonnax Parts Distributor.