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Fiat Allis 14c transmission or torque converter issues

Discussion in 'Dozers' started by anthonys99, Nov 12, 2012.

  1. anthonys99

    anthonys99 New Member

    Nov 12, 2012
    I am having trouble with my 14c dozer. Works fine when cold but once it warms up, the torque converter will not stay engaged. We had a local mechanic come by and check pressure on trans pump and it was in specs while cold. We were going to run it a little more and get it warm then retest the pressure but the weather has not allowed, does anyone else have an suggestions. Transmission was rebuilt 200 hours ago and works great. I could use some help.
  2. Cat_man320

    Cat_man320 Well-Known Member

    Nov 11, 2012
    I owned several HD16Bs . don't know if the configuration is the same or not but just below you shifter handle( you have to remove a cover) there is a modulating valve there. There's is also a place to check the engine clutch apply pressure. Its possible you have a spring broke in the modulating valve . There is also a speed control valve there also that might need adjustment. you could be popping out of gear on the transmission . we had to set our 16 up a few times from that valve . Long while ago but i believe you can add shims or small washers to increase the flow to the torque or something like that .
  3. Iowan

    Iowan Active Member

    Jul 20, 2012
    Southern Iowa
    Interested if you have had a chance to find whats causing the problem? I've looked through my manuals and can't seem to find what would cause this however i think cat_man320 is onto something with the modulating valve near as I can tell from the book... good luck!
  4. Queenslander

    Queenslander Senior Member

    Apr 5, 2009
    I assume you've isolated the TC as the problem, ie: the drive shaft stops when the tractor stalls?
    If it performs OK when cold , you would think it is a hydraulic problem as opposed to mechanical failure.
    Iam only a bush mechanic but my understanding is that TC draws its' oil supply from the transmission circuit which runs at 1500kpa/220 psi.
    The convertor circuit runs at a considerably lower pressure which is regulated by an adjustable valve.
    If this valve is stuck open it might stall the tc.
    So I think you need to take the converter pressure reading when the machine stalls, the transmission pressure may well be OK.
    Do you have a service manual?
    Good luck, Greg