Symptoms: Clunky downshifts, Stiff shifts, Unpredictable EDS solenoid control and/or EDS codes. Cause: Original accumulator piston bumpers lose flexibility and become deformed due to prolonged heat and fluid exposure. Solution: Sonnax's drop-in accumulator piston kit restores optimal hydraulic shock absorption and OE functionality to all solenoid-regulated circuits. Excessively firm up/downshift feel or harsh engagement may indicate deformed accumulator piston bumpers in listed units. Original elastomeric (rubber) bumpers often lose their shape, leading to reduced hydraulic damping. Sonnax's direct-replacement accumulator piston kit 95740-15K reinstates hydraulic damping with enhanced service life.