6.0 Super Duty Trans

wgamble · Dec 28, 2014

Guys this is my first automatic and first diesel, here the past couple of days when I start driving after coming to a complete stop it will rev up between 2nd and 3rd, then power down and then run through the gears normally. What is up with that?

clemsonjeep · Dec 29, 2014

I know you said 2-3 but are you sure it isn't the transition from 3rd to 5th? In "normal" mode these trans shift 1-2-3-5-6 and only use 4th when in tow/haul. When I first crank mine up in the colder months and head down the road I get a slight rev up going between 3rd and 5th. You can order a "better" solenoid to correct this, but a lot of people that don't haul most of the time say that it makes the shift really firm...somewhat aggravating even.

I've also noticed that when it's cold out that the motor likes to run "lean" for the first few minutes. That's probably not the right terminology, but what I mean is that until it gets a little heat built up that it seems to rev quicker than normal and then it drops off once it gets moving. This might be what you're describing. Once the motor and trans get the slightest bit of heat built up it runs like a top...just doesn't seem to like colder temps.

wgamble · Dec 29, 2014

oh forgot to mention that I am a dumbass, I forgot one small tidbit

Once it does this then the tow/haul light starts blinking no matter what. If I turn the truck off and start it back up then the light goes off until the trans does it again.

clemsonjeep · Dec 29, 2014

Ok that helps....well kinda anyway. The codes can be pulled on the transmission to tell you what is going on. The problem is that I don't think all code readers will pick them up...probably has to be a Ford Dealer with the right equipment. I've read a few times where people have had issues with the temp sensor going out, and a few others where the solenoids get stuck and that will cause weird shifting and the light to flash.

Sounds like you better get it checked out before it turns into something worse...