help please truck lost 2nd and 3rd . drop pan ,changed fluid and filter. blow out the cooler lines , removed check ball . test drove shifted fine drove about 5 miles starting and stoping then lost 2nd and 3rd again . 1st and reverse are ok .
dusty if your out there what do you think ?
thanks for your help

 

my truck did the same thing. i took it in and they had to replace the valve body to fix it.