Awhile driving on the highway between 50-60 mph it start jerking like kicking out or in overdrive. If anyone know of this problem please let me know so I know what it is.

 

having same issue in my 99 blazer, after changing the transmission 2 times with no change i finally checked fuel pressure thinking maybe it was an engine miss that was causing computer to go into limp home mode and i have low pressure. now to find out why the pressure is low