I have a 2003 HO towing a 8,000lb travel trailer.

This weekend was the first trip out with the new truck towing the trailer. I drove across Iowa and into Nebraska.

The dang truck shifted down out of overdrive at almost every grade. It just seems like this truck has no power. It could barely do 75MPH on level ground. (I didn't drive 75MPH for long.)

My 7.3 Powerstroke on the same trip last year almost never shifted out of overdrive and we drove faster for the most part.

Any ideas or I am just out of luck? I thought the Cummins was supposed to be an absolute towing machine?

Brian Elfert

 

Fuel filter?

 

how many miles do u have on your truck? perhaps something like band adjustment in the tranny or changing trans fluid would help if they are due for a changing. Doesnt sound quite right to be shitfting that much in those areas. I pulled a 12,700 load in a box trailer from St Louis MO, to Abilene TX. and it only shifted a little if i let it lug down the engine in the hills of MO and Arkansas.
It could be the fuel filter, it could also be the tranny controller, it is seperate from the ECM on the 03's there was a recall a couple months ago about them. Call you dealership and have them take a look at it is what i would do. We also have a couple of 03 QC 4x4 Duallies and havent had that problem except when getting upwards of 20,000# (on flat ground at least)

 

There are right around 4,000 miles on the truck after towing my 8,000lb travel trailer 1,000 miles this past weekend.

I have had both recalls done. I could take it to the dealer, but they would probably just tell me nothing is wrong especially since they drive it empty.

I figured the extra HP in the Cummins would at least do as well as my old Powerstroke.

Brian Elfert

 

Was your PSD chipped or otherwise modded?

Are the gear ratios comparable?

Truck weights? E.G., are you comparing a Dodge QC dually 4x4 to a Ford 2wd standard cab short bed?

I haven't towed with mine yet but seat-of-the-pants-meter tells me this is one pullin' machine. I had a mild programmer (PPIII) on my PSD Ext cab 2wd. You can see from my sig that my new ride is heavier. Even so, my expectation is that it will pull my 5er as well or better. I'll report on that later after this thing is broken in.

Neil

 

My old was a crew cab and new is quad cab. Both are/were 4WD and 3.73. The weight between the two is within about 100 pounds of each other on the truck itself. (Scaled them both.)

I had a short bed SRW before and a long bed DRW now. The extra two tires matter, but the weight is the same so bed length really doesn't matter.

Yes, I did use a 40HP chip with the Ford, but it pulled as well or better than the Dodge before I chipped it.

Brian Elfert

 

I could be mistaken but i do believe the cummins has a broader flatter torque curve than your old truck did. I would take it into the dealership and complain of odd shifting in and out of OD they may find that the TPS is out of whack or who knows, but I wouldnt think it would continue to shift back and forth like that.

 

You said that it shifted out of O/D at every grade. At what speed was it shifting out of O/D? At any RPM below 1800 I would expect it to shift to 3rd on a grade with 3.73 rear end.

 

I could be mistaken, but wasn't there some TSB for a reflash for lack of power while towing?

edit: this one...

http://dodgeram.info/tsb/2003/18-027-03.htm

or did you already have it done?

 

I just got back from a camping trip with our 6,600 lbs camper. I set the cruise control to 50 mph (break-in recommendation.) At 1,400 rpm, it didn't even unlock the torque converter on some mildly steep hills < 3%. I did manually select tow/haul when I got to 5 miles of 6%. But, the truck never shifted out of OD or unlock the TC on its own.

Very cool, very strong.

David

 

The main issue addressed by that TSB seems to be for the 47RE, not the 48RE.

The truck may have been reflashed at one of my service visits. It has one of those stickers they install when the truck has been reflashed.

Brian Elfert

 

Sure, at 50 MPH I never would have shifted out of overdrive either.

I had the cruise set anywhere from 65MPH to 72 MPH. My 7.3 Powerstoke on the same stretch of road at the same speeds didn't shift out of overdrive nearly as often. (The speed limit in Nebraska is 75MPH.)

Brian Elfert

 

ummm, just curious if this is what u meant or not....

u said it wouldnt shift out of overdrive at 55 but would at 70???

That makes no sense. There would have to be EXTREME headwind and drag to play a factor that would cause a downshift at a higher rpm and speed. If you didnt downshift at 55 but had to at 70 either the laws of physics have been revoked or something is outta whack big time...

 

Forgive me if I missed something, I did not read the other replys. I have a SO Kali version and pull 13k pull trailer all the time. I could take it to 100mph if I wanted and pull at 80 all the time. I get down to 50 on the big grades but grunt through many hills without so much as a downshift. I want to get the TST but only because I would like to stay above 60mph on the grades. If you can't stay above 70mph on the flats with a HO, something does not sound right. What's your gearing?

 

Well I have the same problem. My 2000 powerstroke runs with the cruise set at 75 mph and never drops to 74mph on a 4% or less grade. Greater than 4% it will drop out of overdrive but will stay at 75mph up to 6% or less. The Dodge 555 will not hold 70mph on the same road with the same trailer and constantly downshifts. Not only that but the 7mpg sucks. HELP!!!!!!!!!!

JD