Originally Posted by AlaskanTaco
Having the torque converter lock and unlock manually is a BAD idea. The only people that really need them are the diesel crowd and the drag racers. The converter locks up at 30-40 mph anyways and stays locked up until you either A. Tap the breaks. B. slow down. There is absolutely no reason for this at all unless you are doing trailer pull competition or getting ready to run a 10.68 in a 1/4 mile. It is way better on gas milage, and the engineers design them to 1. Last for a long time, and 2. Allow for the maximum gas milage possible out of the vehicle. Don't mess with the tranny! Trust me, I was a trans tech for years for GM and there where very limited thing that you needed to do on a 4l60e to make it last longer and a little more efficient.
Diesel fapper!!-j/k. When the trans shifts with the converter locked under load, it is extremely hard on internals, shafts mostly. Coming from a diesel racing background I've seen first hand what happens to internals when you lock the converter. And those were sometimes even built trans with billet shafts. Most of the time is was dingus with a programmer and a stock trans. Those go boom in a hurry.