tranny od overdrive

I have a 95 1500 360 auto, it had been working fine and last night on the way home from work i noticed the overdrive not engaging every time that it should. It was about 30 degrees outside. Then this morning I went out and it was even warmer outside and it was doing the same thing except worse...

My 1994 1500 4x4 dose not seem to be shifting into over drive. Other than that it shifts fine. The fluid and filter have recently been changed I have adjusted the t.v. cable with no luck and it is not throwing any trouble codes. Some one said it might be the torque converter but I'm hoping it...