Originally Posted by horse1
Originally Posted by saddlesore
Never tow medium to heavy loads with OD locked in. Surefire way to torch the auto tranny


You lock out 5th and 6th When you tow in your new Duramax?


When in mountainous country. Use the tow mode and decide when you want it to shift. grades. Lock out 5th and 6th and slow down and let it pull. Really steep pulls , lock out 4th at times. It all depends how much I am hauling and pulling. I run about 16,000 pounds in my hunting rig.Truck camper, trailer

Originally Posted by ajmorell
It’s not overdrive that will kill a transmission, it’s long hard pulls with an unlocked torque converter


And when it is unlocked , the 6th or 5th gear is essentially overdrive.There is no switch anymore where you select OD. If you let the computer constantly select the highest gear the truck will pull in, it will continuously shift.That will shorten the life of the transmission .Probably in flat land there is not a problem. Where I drive there is. Foothills and two 10,000 ft passes to get where I hunt. Even around home at 7600 feet I have serious hills

Last edited by saddlesore; 01/07/20.
If God wanted you to walk and carry things on your back, He would not have invented stirrups and pack saddles