4l80E wont WOT shift

[JHForman]

Trying to figure out why the truck wont shift if its held to the floor? I have used the Bluecat trans software to set the trans up. Its a built 4l80E with an FTI 3600 stall, AWD, 3.73 diffs, and 285/50/20 tires. If I hold it to the floor the truck will not shift, if I barely ease of the throttle it will shift. Ive played with the shift speeds and RPMs and still cant seem to get it right. I have went higher and lower but nothing drastic. I'm assuming this has something to do with the speed, but my speed is set fairly lower then what it actually shows on the scan so the speed flag should been met and just waiting for the RPM flag.

[Rhin0]

Any luck? I'm having the same problem

[Lakegoat]

Looks like you are at 90mph at 5880 rpm on your 2-3 shift. If your mph shift speed is 89 mph, it needs to be 4-5 mph lower to shift ( set to 84-85 mph). I don't see a full throttle pull, so it is hard to check the other shift points.

[JHForman]

here is what I found, if you do a segment swap like I did the gear calculator is wrong. if you take a 4l80e file and you change the gear/tire wizard to your gears/tires the trans rev/mile is different than if you segment swap and change. its hard to explain but its under speedo trans rev/mile. so to get this right take the stock 4l80e file, put in your gear ratio and tire sizes copy the trans rev/mile it gives you. then segment swap it and put this number in it fixed mine wot shifts are no longer an issue.

[Rhin0]

Great find! I've been having wot shift problems. I just put my gear and tire in a stock 80e tune file and the rev/mile is different than mine. I'm gonna try those numbers and see what happens

[JHForman]

Great find! I've been having wot shift problems. I just put my gear and tire in a stock 80e tune file and the rev/mile is different than mine. I'm gonna try those numbers and see what happens

Good luck that took care of mine I used the bluecat software to set shift points I'm pretty happy with mine now!!