[Jackpine]

I think you DO have custom tunes, is that right?

I'm a bit surprised at your +10 shift settings. Bill sets up the shift pressures to be about optimum in his custom tunes, and I've left mine at 0 - the shifts still feel like a "boot" in the rear to me. Bluejay, long time user of custom tunes over on the f150Forum uses only a +6 firmness setting I think on the 3-4 shift.

But, you're talking about downshift, which may be a whole new thing. I wonder if the torque converter is staying locked longer than it should? Possibly try adjusting the TC unlock in the positive direction for 4-3 downshift? It won't hurt anything to try, and I'd try a setting of +5. (You can go all the way to +/- 10 at 3-4, 4-3 upshift/downshift).

If that doesn't work, I expect the Mad Doctor will have to work his magic.

- Jack