04 gt WOT no shift

blackbeast04:

The 3-4 WOT shift is a big no-no. The overdrive band will burn out and then it won't shift from 3 to 4 and you'll need to replace the band.

First thing to check is the fluid level. If it is too low, shifts will be delayed or won't happen. If it is too high, ATF will foam out of the vent and onto the garage floor. The foamy ATF is not so good for the transmission, either.

Read up on the 4R70W: "Transmissions 101" in the Tech Articles section of TCCoA.com. These articles were written by Jerry Wroblewski, a former Ford Transmission Engineer. A couple of the articles describe the J-mod (modifying the separator plate, etc.) that makes the shifts quicker and increases the life of the transmission.

What is in the SCT tune? Does your tuner know about auto transmissions (no flame intended towards the tuner but there are many, many factors that affect the transmission and the shift and lock schedules)?

Welcome to the forum, too!

Chris

I`m guessing you haven`t altered the shift settings with your tuner? Like WOT shift points/shift points/rev limits etc? If you have you can try re installing the original tune and see how that goes.
The original back up tune should still be available to upload to your ECU and could reset and changes you`ve made.

and what nyukgt says. Fluid check etc.

Yea, go into your tune with the programmer and back the WOT shift speed all the way down, and report back what happens. If you are making a lot more power than stock (which you are) or have gears (I don't know, you might), the RPMs are climbing much much faster than stock. It takes a certain amount of time for the transmission to shift after it has been told to. So if the transmission is still being told to shift at the same time as when stock, the RPM may be climbing so much faster that you are reaching redline before the transmission is able to shift. Therefore, it needs to be told to shift at an earlier RPM.

If the transmission fluid isn't low, I suspect this is your problem.

blackbeast04:

Plug the XCal in and connect it to a laptop and datalog the transmission functions. Without data, you will only be guessing at the problem.

What condition is the fluid in? Bright red and that tangy ATF smell or dull red and a bit burnt? If it is the latter then new fluid and filter may help.

HTH,

Chris