I am having an issue with my transmission once it gets to temperature it jumps in and out of gear sometimes it won't shift sometimes it will the overdrive light flashes when it does it. I'm thinking its electrical the transmission has a new torque converter, modified solenoids, shift kit, and new clutch packs the truck has a SCT Programmer not sure what the problem is needs some help PLEASE!

 

Im having the same sort of issue, i even put in a known good tranny and t case and am struggling with this issue as well. doesnt seem like anyone is responding on this site much these days. maybe we can work together. Ive hade a few experienced mechanics look at mine with no luck. so far i have got mine down to a problem with the gear selector controls. do you have any codes or problems cranking over? sometimes mine wont start in park. that was when the problem started. then got worse to the point its not driveable. it seems to happen most when under load from 1st to 2nd

 

Check wiring harness in column. I know its difficult but some chafing where gear selector rubs in column causes some issues. Follow wire for overdrive button inside column. I would also check for codes with good scanner

 

So my tranny issues were because of a short in the clutch fan. My truck was missing the shroud when I got it and just the way it was zipped tied on damaged the wires and make the tranay shift all stupid. Its perfect now!

 

Try unplugging the fan clutch mine was doing the same thing unplugged the fan clutch and fixed changing the fan clutch now