I have a 98 4x4 5.9. I replaced the radiator and the lines that run from tranny to radiator(supply and return) everything was looking good however I hadn't driven it much distance. But today i drove it about a 50 mile trip and right at the end it dropped out of over drive cruising at about 70MPH in upper 40 lower 50s degree ambient temperature. What gives!?!?!?!. I have a tranny cooler to install and haven't yet but it shouldn't over heat that fast or much with NO loading and kinda chilly outside. I even have the tailgate off now so there is less load than stock version. I am kinda at a loss here. guess i will have to take it to the tranny shop to have it looked at but thought i would throw this post up to get input from you all.

 

well took i6t to my local tranny shop this morning. he got into it this afternoon and discovered a low pressure when conducting pressure test externally for the overdrive portion. I will get mor detils tomarrow as I can't remeber what exactly he said and don't want to mis quote him but he siad 350 for the repairs and parts. So i told him go ahead. I will have him install my tranny cooler and filter while he is at it and anything else the tranny needs to have replaced while he has it apart. For no I am going to skip a off road rebuild and when i get ready just order one from aps when I am ready for that. also going to get him to install new U-joints since most of the reataining clips are falling apart from rust and i doubt the innerds of the joints are much better