Engine/Transmission (1994 - 1998) auto trans not shifting into O.D./ lockup

[RKraiza]

Hi there. I need to no were how to adjust the auto in my 96 dodge. Long story short, I just had the transmission redone with new Valve body, electronics and heavy duty tourqe converter installed at a transmission shop. It's been back there twice now in a week with the same problem. It won't shift into O. D. / Lockup until it reaches 55 @ 2400rpm no matter how I drive it. (1st, 2nd, and 3rd are perfect all the time. ) It comes out of O. D. /Lockup at exactly 50mph. I just had the computer reflashed with the updated software at a dealership to no availe. I'm quesing it's a adjustment someware since this erra trans is heavily regulated by mechanical means. If any one has any ideas, please help. thanks, Rich Kraiza 96' dodge ram 2500 T. D. Auto Oo.