4R100 issue after rebuild

[THE FISH BAIT]

Fresh rebuild and upgrade on my 4r100 now the trans is flaring 300rpm right before shifting into 4th with my hydra installed. Box code is NVK3, i'm using the VRAA6S3 files. It happens in all of the tunes from 25hp tow to 120hp race. The trans guy drove the truck with out the chip and claims that he isn't seeing any issues with the trans. All of the other gears shift good. I'm open to any suggestions yall might have.

[elementaltoad]

Oddly I am having the same issue with my 2001 Excursion. I don't recall the box code at the moment, but I recall the software running a quick update, then I cleared and reloaded the files on the chip. I went from 10 down to 5 of my favorites.

The tune I ran daily, the 140 Extreme, no longer shifts properly, it flares going into 4th gear, as if unlocking in 3rd, causing a flare while shifting to 4th, and then relocking. I've noticed the relock or shift into 4th, whichever it actually is, is very slow. Almost like slowing letting the clutch out in a manual transmission.

I could picture the clutch material just cooking under immense temps, so I removed that tune and only run the 80hp DD now, which seems to shift better, but still not as confidently as I'd like.

[Power Hungry]

Originally Posted by THE FISH BAIT

Fresh rebuild and upgrade on my 4r100 now the trans is flaring 300rpm right before shifting into 4th with my hydra installed. Box code is NVK3, i'm using the VRAA6S3 files. It happens in all of the tunes from 25hp tow to 120hp race. The trans guy drove the truck with out the chip and claims that he isn't seeing any issues with the trans. All of the other gears shift good. I'm open to any suggestions yall might have.

What happens if you run the VNAAAS3 files? Do you still get the flare?