For about a year or so now, anytime I punch it from a low roll (in D on the shifter), the truck will downshift into 2nd and then 1st. It won't shift directly into 1st gear and it's very annoying. As far as I can tell the tune looks like it is set up correctly. Anyone on here had this problem before?

Tranny is a fully built 4l60e (minus vaccuum modulator and Billet input/output).

 

Hmm, lets see a vid of it.

 

Don't have time to do a vid right now, but basically if I'm going 30, and I punch it, it will downshift once into 2nd real quick for about a second, and then downshift into 1st and rape the tires and upshift into 2nd again. It's spending enough time in 2nd that it picks up enough speed to redline 1st just about.

 

Sounds like tune to me. Maybe downshift mph and rpm are way off.

 

sounds like tune to me. log it and see what the trans is doing with speed, and gear command

 

That is not the trans down shifting twice. That is the converter flashing (loose converters) and then the trans down shifting. My truck does the same thing with my Vig 3800. Kinda feels like a double shift though.

 

No, it's definitely downshifting twice... trust me. I've driven my truck for a long time, I know what the converter flashing feels like.

 

what kind of car?

 

He's talking about his truck.

 

https://www.performancetrucks.net/fo...d.php?t=463725