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Final Drive?

Discussion in 'Excavators' started by cat 302, Jan 22, 2022.

  1. cat 302

    cat 302 Member

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    Hello Folks

    I have a 1993 320L CAT. One final drive is slower then the other. Right hand side only going forward it was doing it before and then stopped and now it has returned. It almost sounds like a hissing sound or something is not opening all the way. The Machine is getting up to around 10000hrs and I was told the hydraulic pump may start to fail around now. However because it is only doing this in That one direction I am not sure.
     
  2. Nige

    Nige Senior Member

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    G..G..G..Granville.........!! Fetch your cloth.
    Have you re-sealed the centre swivel since you had the machine.? That would problaby be the first place to start on a machine of this age, the seals will likely have gone hard and probably fallen apart by now.
    Also you could check the flow from the travel motor case drain hoses and compare the LH & RH side flow to identify if the problem is in the motor.
    A Serial Number always helps when locating Part Numbers, etc. Especially for something as common as a 320 where there are probably 50 different variations.
     
    BigWrench55 and Mike L like this.
  3. cat 302

    cat 302 Member

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    9kk00748 is the number for the machine.
     
  4. Nige

    Nige Senior Member

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    G..G..G..Granville.........!! Fetch your cloth.
    On a machine the age of yours built July 1993 this is the first thing I would suspect.
    It has a load of seals (#7 & 8) inside that keep the oil in the different travel motor, brake, etc, circuits apart from one another. These seals go hard and crack over time and can allow the oil flow from one circuit to go into another. Personally this is the first place I would start if you do not have confirmation of a recent re-seal.

    upload_2022-1-23_9-32-4.png upload_2022-1-23_9-34-29.png
     
  5. cat 302

    cat 302 Member

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    When it first started happening I replaced the seals. It did not make a difference. It seems to come and go a bit almost like something blocked or not opening all the way.
     
  6. cat 302

    cat 302 Member

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    This only happens on the right hand track and only moving forward.
     
  7. Mobiltech

    Mobiltech Senior Member

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    Sask.
    Sounds like a relief valve problem in the counterbalance valve on the back of the drive motor. You could try swapping relief valves to see if the direction of the problem changes.
     
    BigWrench55 likes this.
  8. cat 302

    cat 302 Member

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    Thanks I will check that out. It went away before I was climbing a steep hill working it hard and it just started working but then went back to being slow. Makes a sound like when your only on the pedals half way.

    would anyone happen to have a diagram of the relief valve?

    Thanks
     
  9. cat 302

    cat 302 Member

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    canada
    Anyone know a good place to buy used parts in Canada