Trans shifts at 2x the commanded speed and RPM.

[Toro Toro]

I installed a 4L80 trans out of a 99 dually in my 05 GTO a few years back. It was shifting perfect in both normal driving and under WOT for at least 2 years. I removed the trans to install a new engine in the car this past winter and ever since then the trans will not shift under WOT. I have checked all the wiring, replaced the speed sensor at the rear of the trans. and still nothing.

Playing with the tune I found figured out that if I reduce everything (Speed and Throttle) by 50% it would shift. Example 1-2 shift set at 18 mph @ 5500 actually shifts at 42 mph @ 6700
I did some searching but came up dry. Any guesses?

See attached

[Ben Charles]

I’ve seen this before and I believe the speed sensors needed to be swapped

[Toro Toro]

I replaced the rear sensor with a new unit last week as well. I'm not using the front sensor. It was working fine without it wired up for about 2 years.