Tow/Haul? ANSWER IS

[dennis7366]

And the answer is: Bad Tow/Haul selector....Service rep and I took the truck without any trailer and at 60 to 65 mph with cruise on and then selected tow/haul it dropped overdrive went to 2600 rpm and stayed that way. It's fixed now and even pulling the 10k trailer it slides into overdrive at about 50 mph.. Thanks everybody..you gave me the info that lead to the real problem. Have a 2007 Dodge 2500 with 5.9 Diesel. Looking to a buy Montana RL2955. Currently pulling 10,000 lb travel trailer and have not had to go to Tow/Haul mode. Truck runs great at 6o mph in overdrive at about 14MPG and has yet to downshift on Florida roads. Predecessor 5.7 gas hemi always in tow/haul or continuously shifting. Can I expect the extra weight of the 2955RL require tow/haul full time on the diesel?
Based on replies I may be having a transmission problem....while towing the travel trailer at 62mph happily in overdrive and at over 12MPG on the computer. WHEN I engage tow/haul it immediately drops overdrive, RPM goes up about 600 and the MPG goes to 8-9 and that's where it stays. Never up shifts....that's on flat I-95 in Florida

[TLightning]

Don't know about Dodges, but the GM manual says to use the T/H when the GCW is 75% or more than the GCWR. For me, those numbers are 17,625 and 23,500. I think the Allison is smarter than most of us anyway.

[dscott]

The dealer told me that the transmission talks to the motor through the computer,put it in Tow/Haul and don't worry about it.

[Montana Sky]

I run with the tow haul on, just set it and forget about it. Tranny will shift into O/D around 60 mph when in tow haul.

[sailer]

I use tow haul on my f250 all the time i'm towing that gives the brake also in the trane john

[Delaine and Lindy]

When towing I always run in the Tow Haul mode, thats what its designed for. The Allison will take care of the Duramax. But I do get better fuel mileage when I don't use the cruise control.

Montana Sky is correct the OD we hit at about 60. DW and me are going today to get our new 2008 Chevy Silverado 3500 DRW and loaded... However we don't have a 5th wheel to tow. We sold the Cambridge and the 2007 Chevy Classic as a package. We will never be able to replace the Cambridge . Sure wish the Big Sky had the same head room in the bed room area. GBY...

[BB_TX]

I have a Ford so normal operation may be different than your Dodge. But I always use T/H when towing. Once I go over about 62-63 and it shifts into OD, it stays there on relatively flat highway. Will down shift when starting up a hill and quickly go back to OD after I top out.

[tjuhl]

Dennis7366
Have '06 2500 Dodge just like yours pulling 3000RK, just finished a 4200 mile trip. I have found that normal towing using Tow Haul (one push of the button) or not using it, is exactly the same, will shift the same and will go into overdrive at 50 mph. The difference I see is when you slow down the T-H mode will cause the trans to downshift therefore using the engine as somewhat of a break. Yes, if I push the button while moving down the highway it will downshift but will go back into overdrive in about 12 seconds. Now pushing that botton twice does lock out overdrive. Did I make any sense?
My mpg computer is not accurate, always shows better then I am really getting.

[1Happycamper]

I have a 2004.5 Dodge 2500 CTD and pull the trailer in drive. The only time I use t/h mode is on long grades. Never had a problem.

Bill

[clutch]

Dodge probably put the tow-haul button on the truck because every one else has one on their trucks. Actually the extra rpm's are necessary to maintain line pressure in the transmission so everything stays tightly engaged when towing a heavy load. Not using the T-H will eventually show up.

[Pete Hanson]

I have an '04 Dodge (diesel) and generally do not use the tow/haul feature on the highway unless I feel the engine beginning to labor some on an incline. I don't wait for it to downshift on its own because I feel it waits too long to do so. On back roads here in New England I generally put it in the tow/haul position due to the slower speeds and the many ups and downs of the roads. This seems to work well for us and the TV seems to be doing ok with it as well.

[H. John Kohl]

Glad you were able to get it fixed. Best of luck and Happy Thanksgiving.

[Wallnut]

I use the T/H mode when loaded to improve on braking. I've towed without it and the truck had no problem pulling the load, but stopping is reduced. MPG is about the same running at around 65.