I recently installed a Transgo reprogramming kit and a sonnax Servo release check valve into a trans I had that had low mileage on it. I installed a new separator plate and a corvette servo at the time. The trans went from soft mushy short shifts to a really nice not too soft, not too firm shift. I also installed a B&M shift point kit and got the shifts right where I want them. So far so good, but I have an issue with it. Just driving around it works good, full throttle it works good. However there is a point in the throttle, probably in the 50-70% range, where if you try to briskly accelerate it will miss the 2-3 shift completely. It just goes into neutral instead of shifting and I have to back off the throttle to make it shift. I suspect the sonnax valve but honestly that is just a guess. Does anyone have any suggestions where to start regarding this. FYI this is the valve I am speaking about. Thanks, Roy
http://www.ebay.com/itm/700-700R4-4L...-/320735673115

With the TransGo kit you cannot use the Sonnax valve as it conflicts with the kit. TransGo will tell you the same thing here. Their kit addresses the 2-3 & 3-2 shift problem a different way.

So would you say I just pull the valve out and put everything back together without it? I got an email response from Sonnax where they recommended I check the 2-3 spring and check the factory accumulator valve for leakage, but never mentioned any incompatibility issues. Have you seen this problem before? Thanks for helping me.
Roy