As others here have report, my 48RE with an ATS stand alone controller was a bit of a dissapointment at the start. TC lockup in 3rd was very harsh as was the 3-4 shift while the TC was locked and setting the 'unlock during shift' option seemed not to work.

But my pretty much stock TC died (for reason that are still not clear) and we replaced it with a high end triple disc TC. Now, lockup in 3rd is nice and smooth and the TC will unlock for the 3-4 shift. But that felt weird so I turned it off and the 3-4 shift lock is fine - a little firm but that's OK.

So the problem that I had assumed was 48RE related was really driven by the TC...strange. But I'm happy to have everything working better. I can now get lock up in the mid 30's and stay locked. The only thing I am still fiddling with is unlock. Apparently if you set 3rd as you lowest gear to lock up, it will still stay locked through the 3-2 down shift if your speed is set low enough in the graph. The challenge is that when coming to a stop the locked TC actually lugs the engine in 3rd and 2nd. I may dry 'unlock during downshift' to see if that helps - but that will reduce engine braking while towing during shifts - I'll have to see if I can set up the B calibration on way and the A calibration another.

Peter

 

Interesting... I need to get a laptop and do some more tuning with mine.