My 1994 6. cyl Mustang automatic transmission gets neutral when running at 50/60MPH and engine is warm up.I have to lower the RPM and speed in order to get the proper speed.I hace changed old transmiison and mounted a new one and nothing happened, also I change the Transmission computer and the problem persits
I have visited more than 1o dealersm they have scanned the car and found nothing
SInce it is a very extrange problem and I want to keep my Mustang( has only 70.000 miles) I will appreciate any comment or any help, god bless you

You say you had it to a dealership and that you cahanged transmission has anyone put a scanner on it and drove it down the road to check things like the speed sensor, and MLP switch(also known as the neutral safety switch). Another thing is some models of the AODE(4R70W) was recomended adding another quart of trans fluid because at high speeds the pan would not have enough fluid in it .
Let me know:)