Just got my truck couple months ago... By the way I just love it !!!

Anyway I seem to have problems with towing performance. I have a 28 ft travel trailer (~7k) and I just did my first 200 mile tow and had difficulty maintaining 70 mph on moderate hills. It would slow to about 55 mph, shift to 3rd and rev at about 2300 but no increase in speed.
Idles great - steady at about 725 RPM. Starts great and runs around town great. I have changed the engine oil (changed to premuin Blue Extreme synthetic), Fuel filter, Trans oil (flush/filter and band adjustment), x-case oil, f & r axle oil. I don't know if this applies to my truck, but I also did an APPS reset.
Seems to have excellent power to 60 mph but above 60 mph it is a tired dog !!
Sorry...but I have no gauges to report on
Could this be a lift pump issue ? Do I have some un-real expectations ?

If it is the lift pump, is it covered under any warranty (i.e drivetrain or engine)?

Thanks to anyone who would like to comment or provide suggestions

 

Lets see, 28ft TT(BARN DOOR), Pulling to 70mph and slows to about 55 on the hills but run like a banchie doing it.
NORMAL
If it it is pulling the hills at 55 and maintaining it thru the hill, then it sounds normal.
I just finished a coast tocoast run pulling my 5VR and would pull most mountain passes at 53mph. Of course I was passing everything on the road on the way up. Most trucks just couldn't believe how fast I was catching them and leaving them on the hills
Set your cruz at about 68 and let it ride

 

Thanks for the reply SuperGewl...now here is the real problem
My buddy has an '04 Duramax (no performance mods). I followed him on the same route the week before my first tow. He was pulling a similar trailer to mine and I was empty. The whole route he never dropped below 75 MPH !!

We are scheduled to vacation together in another week and we will both be pulling our barn-doors through the mountains.
My big concern is that if he continually leaves me behind...I will have to spend the entire vacation mixing the drinks.

I have read the DC warranty very carefully and can not see where DC will reimburse for whisky !!

The only consolation is that he has to sit in in a GMC the entire trip while I get to sit in a Dodge RAM....and I guess that is worth a few drinks

 

Time to put a box on. Don't forget the pyro gauge.

How about the air filter?

 

Well since that sounds normal if I where you I would definently throw some gauges on there BEFORE the trip so you can get some readings. Also you might look into a box and intake. That'll help ALOT. As for gauges: Boost, EGT, Fuel Pressure.

 

I thought a CTD would not even down shift going up a hill with a load like that? I thought once you got that Cummins going, you could set cruise and leave it? I towed a 10,000lb load with a 7.3 Stroker , up hills and I barely had to push the pedal any more. The truck didn't downshift or lug down.
Between the D-Max, PS and CTD which one would be the last to lug down and down shift?

 

Depends on gear ratio and tire size as well. The BEAUTY of the cummins is that stock vs stock it may not be the fastest, but it will be the most reliable. Drop a box on there and watch out!

 

Wrong gear for towing a barn for one.4.10s !

 

Thanks to everyone that replied.....
I am not a bomber....but I do appreciate those that do modifications. By stressing the engine and other components, they reveal the weak components and provide people like me with a ton of information on what we can look to when we have a malfunction.

I will keep everything stock...at least until after the warrantly expires.

 

Try down shifting to third before slowing down to 55mph. You should be able to maintain 60-65mph easy in 3rd gear lock-up. Let that little puppy spin at about 2500-2700rpm and you will be amazed what hills you can climb.

PS, It wouldn't hurt anything to drill out your airbox to let some more air in. Your engine will love you for it!!

 

Can you someone explain the "drill your airbox" deal, and what does that do overall for the engine? Are there pics on how to do this?

 

Check out my photo gallery. Picture is worth a thousand words. The modification lets more air into the filter box, thus more air to turbo and engine.
Do a search, has been lots of threads and pictures on this proceedure.