Since I bought my 06 Navi having 80k on the clock, I don't have a baseline for my experience here... As in I don't know what it did when it was new and was working presumably as it should.

Basically it is downshifting during deceleration. Now I understand that a transmission should do this under normal circumstances but the degree in which my Navi is doing it has at least caught my attention.

What most auto-transmissions won't do is downshift (without moving the shifter to a lower gear setting) in a manner which actually slows the vehicle down. Perhaps this is normal for this vehicle... I don't know. But it does occassionally do it a bit more aggressively creating a noticeable creaking noise in the drivetrain; this is not often but a couple times a week. Not sure where the noise is coming from.

So anyway here is a video of the tach where you can see the engine speed increase a bit as the transmission downshifts during deceleration. It will do this throughout all the gears if I am slowing from anywhere above 55mph. I was trying to be safe and get a video while going slower to illustrate my point.

The downshift occurs around the 11 second mark. Forgive the soundtrack... Let me know if the link doesnt work.

http://youtu.be/YbUXqQy_qUk

 

I guess I can't embed a video on my phone...

<iframe width="560" height="315" src="//www.youtube.com/embed/YbUXqQy_qUk" frameborder="0" allowfullscreen></iframe>

 

My concern is that there could be a faulty shift solenoid or something that could cause premature tranny wear or failure if left unresolved. It is also possible (albeit unlikely) that this thing has some sort shift kit in it as there seems to be some sort of towing (or maybe gps (idk hate sounding dumb but I can't figure out what it is)) related aftermarket electronic device stuck to the windshield. This is how my inlaws Chevy was shifting when I was playing with the tow mode button on their truck; I couldn't find a tow mode for the Navi. I did ensure the advance trac thing was off.

Thanks!

 

At 20 MPH downshifting out of OD or 3rd would not be unreasonable. You haven't really given us too many specifics like all of the downshift points to be able to give you a more precise answer.

 

Are you asking for the vehicle speed at the downshift point? I am happy to get more specific but not sure what is needed... Not even sure if there is an issue. Just seems weird that its downshifting in a manner that slows the vehicle down. If I were shifting it manually this would be how I would expect it to operate.

 

Most vehicle do this, it's just not noticed because people generally press the brakes to slow down and do not wait for the tranny to downshift and slow them down.

 

Sounds normal to me. I have the same truck and it also downshifts. Think ford named it "torque on demand", or something like that.