I just started towing a 6000 pound trailer and my F250 won't shift into overdrive. It stays at 2200 RPMs and when I press the overdrive button it doesn't shift at all so I know its not shifting into OD. I remember something that I read in these forums about this. Can someone point me in the right direction?

 

Go back and re-program the Superchip. Follow the directions completely. You shouldn't have any problems in the tow mode.

 

I have had this programmed this way for 3 years with no problems so I doubt that I didn't follow the instructions. Anyway, I found an old post by Mike Troyer that explained some problems they with it shifting into overdrive.

Tomorrow I call Superchips.

Here is an old post from Mike T.

"It's rare to actually need to do any manual adjustments in the 1997-2003 trucks & SUV's, generally speaking. There is one neat driveability "trick" we like to do with regard to the shift points that helps the truck get back up into Overdrive quicker after a downshift - there is only 1 change to make, and that is to bump the 2-3 upshift point up exactly 2 notches (lines) above the centerline (ST). Leave all other shift points alone, they have already been optimized for best WOT acceleration. This 2-3 adjustment I'm talking about actually helps these trucks get back up into *4th* gear (Overdrive) quicker after going up a hill or grade (a load event), or after accelerating, etc., and that is why we advise doing that. This one small adjustment usually does not slow most of these trucks down appreciably in their 1/4 mile times. Aside from that one driveability trick bumping up the 2-3 upshift point 2 notches that helps get it back up into Overdrive after going up a grade, we advise leaving all other shift points as per the default upload from the Micro Tuner in the 1997-2003 vehicles."

 

Does it shift into OD without the trailer? My guess is that the PCM realizes that the 5.4 doesn't have the power to pull 6000 lbs in OD, and won't shift up unless it is under very little load, ie downhill. A 5.4 will struggle to maintain highway speeds with the converter locked in third gear, much less OD.

 

I adjusted the shift points as in my post earlier and it shifted just fine undering towing conditions.