What speed should an auto trans be shifting into Overdrive under normal circumstances?

When mines cold it won't to into O/D till I'm going 50-55 (usually closer to 55).

It does it sometimes even when it's warmed up, flat ground, no load.

 

mine used to do it around 47 when I adjusted the bands it went up a little, like 52

 

Also depends on what size tires you're running. I believe is shifts on RPM so if tires are changed it will change the OD speed. Also depends on if you have it floored or not. With an easy throttle, mine used to do it at around 45 but now not until 50 with the larger tires....