Conventional GM Powerglide servos are not well-supported. At high apply pressures or with a worn servo pin bore, the servo piston is side-loaded in the case, causing friction and binding of the piston. The unique Sonnax supported servo pin and cover kit 28821-19K eliminates friction caused by side-loading and ensures the servo piston will apply and release without binding.

• Unique design eliminates piston binding that causes unexplained band failure
• Low-drag O-ring prevents high gear & release oil pressure bore leaks
• Compatible with all OE and aftermarket Powerglide servo pistons