Overdrive or not?
I finally purchased my first three quarter ton suburban with 8.1 motor. Until now I had a half ton with 350. I always towed in third gear because I understood that towing in overdrive was a no no. Now...
Forum Discussion
3oaks wrote:majorgator wrote:No one here said the Tow/Haul mode would keep a vehicle out of overdrive. But the tow/haul mode will automatically select the right gears and keep the transmission from continually hunting through the gears including overdrive.Jack_Diane_Freedom wrote:
Just engage the tow haul button and go the computer will select the right gear.
This is not entirely accurate. While the Tow/Haul button will change shift points and thus prevent you from advancing gears at the lower RPM's, it will not keep you out of overdrive during heavy tow modes. The best and really only useful way to determine if OD is OK is to drive and experience it yourself. If it's shifting in/out of OD frequently, then don't run there. Keep an eye on trans temps and monitor the shifting.
When towing, I like others select the Tow/haul mode. Set it and forget it. That's what it's there for. Takes the guess work out of which gear to manually select or lock the transmission out of.
I have a HD2500 Chevrolet Duramax and utilize the tow/haul mode when ever the unit is loaded or towing. The t/h mode raises the shift points and reduces transmission heat. The vehicle doesn't shift in to overdrive until apx 62 MPH. The t/h mode also utilizes the engine brake and towing in manual mode also let me control/limit the shifting of the transmission. Let the computer do its job, if it searches during those occasional steep inclines restrict the transmission with the paddle switch on the shifting lever.
