5.9 auto trans questions

I've got a 2000 2500 4X4 turbo diesel, the converter seems to lock up between 2nd and drive which sometimes makes the tranny shutter. I've heard the dealers can "flash" the tcm and make the converter lock up only at highway speed or only in OD, but my local dealer said that all he can do is change a spring in the valve body to move the lockup speed up. also I read about a trans-go shift kit that raises the line presure. does anyone know what can be changed with the tcm flash? does anyone have a shift kit in their truck?

Lockup and Overdrive are both controled by solenoids on the valve body they get turned on/off by the computer.

There is some programs available from Dodge to change shifting schedule don't know if it will address your concern though

thanks for the help, i'm taking my truck to the dealer for a trans service , their going to flash my tcm with updates and reset for my tire size and also adjust the two bands in the transmition. thanks again.