Eaton 2 Speed axle stuck in Low

Discussion in 'Kenworth Forum' started by OldRed98, May 12, 2021.

  1. OldRed98

    OldRed98 Light Load Member

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    Hello,

    I have a 1986 Kenworth Tandem dump truck. It has a 13 speed Eaton Transmission and a 2 speed Axle. The 2 speed axle switch is on the dash and has a high and Low. I can’t seem to get the axle shifted out of low. My Truck only goes about 55 mph tops. When I flip the switch to high, it doesn’t make any difference. Is it possible that I’m not shifting it to high correctly? I climbed under the truck today and had my wife flip the switch… I can hear it add air to the rear end and release air when shifted back to low. Not sure what the problem could be. Any help is appreciated.
     
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  3. baha

    baha Road Train Member

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    Maybe best to take off the air and air dia/fram 0ff just to see if it has a hole in it and if the arm leading into rear end is still able to move from low to hi by hand or pry tool?
     
    Last edited: May 13, 2021
    OldRed98 Thanks this.
  4. OldRed98

    OldRed98 Light Load Member

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    I’m going to work on this tomorrow. I’ll take off the valve and inspect. I’ll report back what I find. Thank you!
     
  5. OldRed98

    OldRed98 Light Load Member

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    I took off the air diaphragm. Gear rod pulls in an out. Cleaned it all up and put it back together. Still won’t shift to high range. Not sure what else to do. The dump truck still goes almost 60.
     
  6. w9l

    w9l Light Load Member

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    Is it a twin screw? I have never seen a pre 90's truck with twin screw and 2 Spd. Several single axles but not a screw.
     
  7. AModelCat

    AModelCat Road Train Member

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    I know you said the rod moved but were you actually able to manually shift it between ranges and verify that?
     
  8. baha

    baha Road Train Member

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    Make sure that the rubber is put in the right way if its in backwards it will not move enough to move the arm to switch gears, ck for cracks it it carefully?
     
  9. OldRed98

    OldRed98 Light Load Member

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    Sorry it took me a little while to post an update.

    I raised my dump bed and started tracing air lines. Turns out that the diaphragm I cleaned is for the locking diff. I traced the air line for the 2 speed axle switch and sure enough it’s capped off.

    I don’t see anywhere that this 2 speed switch would plug into the diff. Wondering if someone replaced the rears at some point and eliminated the 2 speed. It’s just odd that my truck only goes about 60mph tops.

    It’s a Kenworth W900 tandem dump truck with a 3406b and Eaton 13 speed.

    I’ve only owned this truck a couple of months and don’t know any prior history on it.
     
  10. w9l

    w9l Light Load Member

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    Need to know tire size and rpm at 60 to make any sensible guess as to what is going on. A 13 direct with 4.30 gears on some form of short rubber comes to mind?
     
    OldRed98 Thanks this.
  11. lester

    lester Road Train Member

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    It's an old dump truck, probably just geared low
     
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