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Overdrive question!

Discussion in 'General Chevy & GM Tech Questions' started by Silverado1500, Jan 5, 2010.

  1. Silverado1500

    Silverado1500 New Member

    in all my life ive been told overdrive was for towing...but its the exact opposite. so that means ive been driving with overdrive off the whole time. would this harm the engine or transmission?
    if so i am going to be very upset about this....

    and just to be sure. overdrive is on when the light is on right? or is the light on as a warning telling you that it is off?
    Last edited: Jan 5, 2010
  2. TMRuiz

    TMRuiz New Member

    It burns alot more fuel than it should but unless you drove around with the tach in the red zone all the time you shouldn't have anything to really worry about as long as you kept up with the maintenance.
  3. Greg84

    Greg84 New Member

    What light are you referring to? I think you might be confusing overdrive with the tow/haul mode..

    Overdrive just means 4th gear in your truck, or technically any gear in a transmission that is lower than 1:1 so the transmission output is turning faster than the input. If you're driving and don't want to use overdrive, you have to have the gear selector on 3 instead. That way it will never shift into 4th gear.

    I'm guessing the light you're talking about is the tow/haul mode, thats usually a button on the end of the shifter or on your dash. It will turn a light on in your gauge cluster when you turn it on, it doesn't hurt anything to drive without hauling anything in this mode, it just burns more gas. This mode changes the way your transmission operates, it raises the shift points for upshifts and gives you a little more engine braking to help slow you down.

    You can tow in overdrive. Double check your owners manual if you want, but even there it says its fine. The only reason you would want to shift out of overdrive is if your truck keeps shifting between 3rd and 4th. It might do this if you're towing a heavy load on the interstate with a lot of headwind or just too much weight for your truck to handle, or possibly when going up a long hill.
  4. silveradotrailblazer

    silveradotrailblazer New Member 1000 Posts

    overdrive question

    X2 what Greg84 said. I have lifted Z-71 with 35s and tow in overdrive with the tow mode on and have over 80,000 miles on truck and no tranny issues.

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