not sure motor or tranny?

[fortric]

Hi All. this is my first post hope you guys can help. I have a 99 F250 PS 4x4. A couple months back I was traveling apout 55mph and developed a shutter(whole truck not steering) pulled off the road and found nothing. after get back on the road all was fine. havn'y had any more problems untill today.At about55mph starting accelerating up and incline and shutter started again.Pulled over put in park back in gear and got back on the road and all was good. about 3 mile later it started again. shutter seems to only happen when accelerating. but this time when traving a steady speed it would feel like something was dragging the power down on the engin. This would come and go.turned around and headed back home.was working fine for a short time then it started again. This time it started pulling the power down again and got so bad I had to pull off the road.when I stopped and put in park the engine shut off. when trying to start back up it will try to start and then shut back off. when truck was stopped and in gear it felt like the power was being pulled down but when in park sounded fine. I think it is my tranny or converter. would bad injectors or anything else cause this. thanks for any help yopu can give

Rick