Rick, pasted below is a conversation about towing. Can you please give us your opinion ?


QUOTE (EXPLORER @ May 21, 2007 08:17 am)
QUOTE (HotRodYJ @ May 20, 2007 07:02 pm)
I toyed with fuel mileage last week pulling down to Sevierville and got it up to 10.5mpg by using OD and no cruise. Driving in OD however can still be really hard oon a transmission even if you drive it so it doesn't shift. I'd rather pay a little more on fuel than replace a transmission so I think I'll go back to the old way of towing. OD turned off and set the cruise on 70mph. I may try 65mph this week and see if I gain any, but I don't expect it'll make that much difference.



I'm pulling a 3900 pound TT with a Chevy Avalanche Z-71 4x4 with a V8. I've been pulling with the OD off until I hit the interstate then flipping it back on.
Maybe that is a mistake. I was told by the dealer that because of the light weight of the TT it would be ok unless the transmission starting shifting in and out of OD. Maybe I better start pulling with the OD off, don't want to replace the transmission.


I always thought as long as it doesn't shift and "search" for the right gear then all is good. I was under the impression that the shifting is what would really kill the trans and drive the trans temperature up. In talking with a guy yesterday, he said that's not necessarily true. Even if it doesn't shift, the OD clutch's and such where never designed to carry the added load and therefore the trans can still heat up and kill itself even if it's not shifting. My Durango does have a trans temperature light on it and it's never come on, but after discussiong this yesterday I think it's probably safer not to use OD and deal with the added cost.

True keep it out of OD when towing.
thats the reason some TV will have a towing button that you press when you hook up to a unit to tow. This takes out the OD.

Hope this helps

Sounds good to me. Thanks Rick

I poked around a little on the net this morning look for a wide variety of opinions. The overwelming opinion from pretty much everybody seems to be, if it doesn't hunt for a gear and the torque convertor locks and stays locked, then OD is okay. If the TC wont stay locked, or it starts shifting then don't use OD. On my Durango, I can watch the Tach and see exactly when the TC locks and unlocks. The RPM's will drop about 200 when this happens. The overwhelming opinion seems to boil down to trans temperature and a TC that isn't locked slips and create's a bunch of heat. Heat kills transmissions. Shifting in and out between 3rd and 4th gear also creates heat and wear as the clutch's slip as they engage and disengage.

I've come to the conclusion the best way to tow, get the best mileage, and save the transmission is to add a transmission temperature gauge so you can monitor the temp and tell if it heats up more in OD than it does when OD is turned off, and of course watch the shifting and TC lock up and keep it to a minimum. My Durango does have a trans temperature idiot light, but a gauge would be really nice. I think I may add one for more testing.

It seems more people actually do use OD than don't from what I've read today.