cd4e tranny problem
 

I freshly rebuilt my CD4E but didn't change the torque converter. I did install a shift kit and new shift solenoid. It started out good but now with around 200 miles on it, when it gets hot it seems like it doesn't want to go into any gear until you rev up the engine, then it acts like a neutral drop into gear. I have checked the fluid level and I did clean out the cooler when it was rebuilt. I did use a Valvoline Max Life Full Synthetic oil Mercon LV. My question is did I use the correct oil? and if so what could cause the issue? maybe a torque converter failure or a bad shift solenoid? Thanks for the help. Chief.