Running with power divider on

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Richter, Aug 12, 2013.

  1. Richter

    Richter Road Train Member

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    Philadelphia Pa
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    Hi,

    I turned my power divider on the other day (340 miles ago) to make sure I did not get stuck at a muddy shipper. I accidentally forgot to turn it off. (The light is behind qualcom) I noticed my mpg was down 1 mpg but figured it was do to the heavy load. How bad was it to run 65mph with the power divider on? (this is the one that locks both axles together, not both sides, I did not have locking diffs on) Was my mpg drop do to having it on or was the load just heavy enough. Did i do major damage to my difs?

    Thanks,
    Cody
     
    TheDude1969 Thanks this.
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  3. BullDoggin

    BullDoggin Light Load Member

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    No damage... no worries. I wouldn't do it on purpose, but you'll be alright.
     
    Richter Thanks this.
  4. Heavyd

    Heavyd Road Train Member

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    If your tire thread thickness is about even axle to axle you'll be fine. The power divider will force the front and rear axle spin at the same speed. This is no problem until the tires are different in circumference due to tread thickness differences. If your front drive is 19/32, and your rear dive is 14/32, that is actually a big difference is circumference when two axles are locked together. The tires now have to scrub slightly as the axles are mechanically forced to spin at the same speed. If you damaged anything, you would know by now!
     
  5. Ezrider_48501

    Ezrider_48501 Road Train Member

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    you would know by now if you damaged something just try to pay closer attention next time. its going to be hard on stuff but if nothing snapped your be ok
     
    Richter Thanks this.
  6. TheDude1969

    TheDude1969 Heavy Load Member

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    Joliet, Il
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    Great question I've not seen asked b4.

    You were putting power to an axle that didn't need it is all you did. Unless you hear or feel something wrong, there is likely no damage.

    Understanding what you did is helpful...
    Damage may occur with worn tires on one axle and brand new on the other thus one axle turns faster than the other. This puts the drive line in a bind and skids the tires over time/miles (aka tire scrub) relative to the different circumference/wear. Thus causing more wear... and internal strains on the differentials. The more one axle turns vs the other the more tire scrub/wear results.

    Hard to say how much of 1mpg is result, but certainly you were turning an axle that didn't need pwr, and the more scrub between axles the more you can assume is a result.
     
    Richter Thanks this.
  7. 379exhd

    379exhd Road Train Member

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    Here's what you need to know about power dividers. Then you will be able to determine how much damage was actually done.

    Here's the link. Good information might be an educational tool for how a power divider actually works as most of us do not actually know how a power divider works.
    http://tow411.yuku.com/topic/78075
     
    TheDude1969 and wore out Thank this.
  8. Richter

    Richter Road Train Member

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    Tires are all new recaps that have very close to the same depth. Thanks for the info. Fuel mpg drop was probably just a heavy load since im not seeing much of an improvement today. I normally hual 10-15k on relatively flat runs. Yesterday and today i've hauled 44k+ on decent hills. the truck still does surprisingly well, but the mpg has dropped.
     
    TheDude1969 Thanks this.
  9. beltrans

    beltrans Medium Load Member

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    So which axle does not get the power with PD unlocked???
     
  10. Ezrider_48501

    Ezrider_48501 Road Train Member

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    they both get power unlocked but the are able to turn at different speeds (ie tire wear differences or one having to travel less distance around a corner than the other due to off tracking ect) having them locked up there will likely be more bind on the drive line and more scrubbing on the tires witch could still lead to a drop in mpg.
     
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