Duramax towing question

[Mark Wiltrakis]

I have a new Chev Duramax to transport my A/S. It has "tow-haul mode" activated by a pushbutton, which makes sense for towing a trailer. Holding the button longer results in "overdrive lockout" which is more mysterious. My Chev dealer suggested that I ALWAYS use the overdrive lockout when towing the trailer to save transmission wear and tear.

Is this what you are doing with your Duramax?? I'm unsure of the benefits of this procedure and would like to hear from others towing with an Allison transmission.

Happy trails!

Mark

[Pick]

Hello Mark! I have a Duramax also. Putting it into the Tow/Haul mode does a couple of things. First it changes the shift points to a higher RPM, then after shifting out of 1st gear it locks the torque converter in all the rest of the gears. It also enables grade braking.

I have found that you can tow while not in T/H just fine. Just watch the transmission temperature. You will get better fuel mileage. When towing, I shift in and out of T/H as the need arises.

I think the dealer does not know what he is talking about when he says to tow with overdrive locked out. You would use this feature while towing in the mountains or steep grades to prevent the transmission from "hunting" between OD and direct, but not on level terrain.

My trans temp runs between 140-160 when towing my Airstream.

[diesel]

Pick hit it right on the nose. Hmm, I better not use those two words in the same sentence again.

I use a 2002 2500HD Duramax Allison to pull my 1995 30' Excella. I only use T/H when going down a steep incline or when I want to cool or not use my brakes.

Since your are from Oregon, climbing up highway 97 either north or south out of the Columbia River Gorge does not require T/H. I have to watch my speed going up Cabbage Hill on I-80 because I could easily roll the trailer over on the curves. I stay out of the far right lane because the OTR trucks are only doing 20 to 30 miles an hour if that. You will have no worries with your tow vehicle.

Before I added the CargoBat under the canopy, the truck alone weighted 8400 pounds. I travel with the fresh water tank full in the trailer and 60 gallons of diesel in the truck.

As Pick said, just watch your transmission temperature. I did add the larger Allison transmission pan and changed to Allison's recommended synthetic transmission fluid, Transyn.

[Cracker]

I'm still looking for more information and feedback on whether or not I should be concerned with the stiff suspension of my dually? Since I'm not riding on the second set of springs, the 3500 is probably not too different from the 2500. I've been looking at the air ride hitch - but I haven't done enough towing with this setup to know whether or not its needed - or desirable. Any thoughts?

[Dwight]

I have a '02 C-3500 C-C dually with the D/A combo. I pull ay 34' Excella and we enjoy the long wheelbase for the ride and the piece of mind of having a second set of tires on the rear in case of a blow out. We also use the Hensley Arrow hitch.

[Cracker]

Dwight:

Did you tow enough before you bought the Hensley to notice a difference in handling - or did you start right out with the Hensley?
Again, I haven't towed enough with this setup to know whether or not I'll ever have a sway problem with the 30' - however, everything I read seems to imply that I won't.

Cracker

[Dwight]

Our '86 34' Excella had a Reese Dual-Cam hitch. We kept it for about 6 months, then bought a Hensley (there was a difference). When we sold our '86, the couple requested that we include the Hensley in the deal. We installed another Hensley on our '99 34' Excella and would not use anything else. A lot of folks in our Unit either use the Dual-Cam or the Hensley. You should try the Hensley if you have any interest. They offer a 60 day money back deal. Yes, it is a lot of money, but it pulls smooth and nice!