full throttle at 80mph won't shift
 

Hey guys im new to this i wanna introduce myself first im from phx az my truck is a 95 dodge ram 5.9 mods: on it ss/t rims , m1 intake manifold , msd 8mm sparkplug wire, msd ignition coil , eletrical fans ,shorty headersand 410 gears , 4/8 drop kit and hypertech module not sure if it does anything though bought it on craigslist. Well this is my 1st truck i installed everthing that has been done to it and since i installed my new rebuilt tranny when i floor it all the way wont pass 80 mph like it wont shift and stays "bucking" but if i let go off the gas a bit it does pass 80mph and shift. i really need help any suggestion or feed back will be greatly appreciated :icon_headbang:

Moving to the correct section. Welcome to DF.

I wonder if at full throttle, the trans normally wouldn't shift until RPM goes higher than what the PCM Rev Limiter allows..... Letting off the gas tells the trans to shift a bit sooner, and prevents you from bouncing off the rev limiter.

Thanks for the information im gonna be checking that out this weekend followed with the tps sensor and speedometer thats on the left side of my tranny :icon_naughty: