What’s going on guys and gals, I have a debacle that i need so insight on. I have a 2004 Silverado 2500 non HD, has the 6.0 and 4l80e. Transmission started to slip and show age, truck has over 200k on the odometer. I decide to buy a new transmission and install it at my shop (no big deal im a mechanic). So i opt to buy on of them monster transmissions 4l80e with a stage 2 shift kit blah blah blah, suppose to be the cream of the crop. I wait 6 weeks for it and install it. Not even 30 miles into to driving the transmission started to over heat (one time going into hot mode) i hook up my snap on soulus and access the transmission data, noticed the torque converter was not locking up when the TCC PWM solenoid would command full lockup. So the converter is trash. i contact monster transmission and they instruct me to remove the unit and send it back for a warranty. They get it back and apparently go though it and it checks out. I get the transmission back after 2 weeks, also got a new torque converter. I reinstall it with the new converter, and what do ya know. Same dam issue, I diagnose it and find the converter has once again failed causing extensive heat and overheating the transmission. I end up buying a new converter for the local auto parts store and it works great, but the transmission is still getting up too the 220 degree mark (average outside temp where i live is 60 degrees), i have bypassed the factory radiator cooler and installed a new 40k cooler and still no change. Lines are clear, no leaks, fluid is topped up correctly and doesn’t smell burnt, transmission shifts great, lockup’s great, overdrive works, doesn’t slip the rear cooler line fitting with the dingus on the end of it is in the right spot, the torque converter input shaft seal is brand new. I’m outa ideas here and monster transmission is little to no help. What should i look at next? Maybe a faulty temp sensor? I’m sure that would throw a high/low circuit code. One thing i have noticed is when it got to 200 degrees i would use my IR temp gun and get a reading from the lines and pan, (line coming from pump was 185, line going back to transmission from cooler was 150 and the pan read 125, Please give me some insight, thanks.