I am supposed to receive the spring kit today from MB. It should be installed next week, I'll let you know if the $2.26 kit cured a over a year of aggravation.
The B-2 Reaction Valve is the brake on cultch plate prior to the shift ( I think). I'm no mechanic but I have looked deep into this problem over the year. If $2.26 fixes the problem, I'll be very pleased and very p!$$ed off over all the money I have put into a vacuum module, 4 flush and fills, several vists for cable adjustments, dropping the pan and filter exchange... But its the brightest trans fluid I have ever seen!