5.0coupe

Driving the car and im about to pass this kid so i put my car in D and thentake off. and at about at like 65 when i put it into overdrive. and it finally shifts later than usual. so then i resume normal drving and the car's rpms are at like 3000 and im going 25mph. its never done that. Then i begin to go faster and the car is still not working properly and it like shifiting hard and just not doing what it is supposed to be doing. Any ideas on what parts of the transmission are possible broken or messed up? Its going to the shop tomorrow to get it flushed and to look thru the pan.

lookin4astang

Torque converter shot maybe? Im not an expert at autos, but that would seem a possibility to me.