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Komatsu D21A-7 transmission problem

clemonsk ยท 2013-01-14 21:53

I was wondering if anyone can give me some insite to my transmission problem? I am finding black particles in my transmission screen that is clogging it up. Eventually, it completely causes the machine to stop moving in all 3 forward & reverse gears. I have changed the oil and cleaned out the filter. This will make it run for a few hours before the screen is clogged again. Any advice would be appreciated.

Replies9
  1. #1JGS Parts2013-01-14 23:39

    Mate is the black stuff magnetic? also is the transmission sounding very loud compared to normal? have you changed oils or anything different lately?

  2. #2MrElectric032013-01-14 23:44

    Once the filter is cleaned it runs fine with no issues? Is it the filter that is clogging or the metal strainer on the pump pickup tube?

  3. #3clemonsk2013-01-15 13:44

    D21a-7 transmission The black stuff is not magnetic at least it does not appear to be. I have changed the oil several times. I even put a new transmission screen in and ran for a good 10-12 hours before acting up. Had to drain oil and clean screen again just so I could get it back to barn for winter.

  4. #4clemonsk2013-01-15 14:22

    It runs fine for the most part, although I've thought all along it should have a little more power in first gear. I'm guessing its just the transmission screen that is clogging because when I clean it out, it starts moving again?

  5. #5mitch5042013-01-15 17:02

    The worry is, what's the black stuff? is your transmission eating itself?

  6. #6JGS Parts2013-01-15 21:39

    yeah i know mitch i am also wondering if it is eating it self as if he has chaned the oil and all the filters and everything where is it coming from ? but if its not super fine bits of metal i wonder what it is?

  7. #7clemonsk2013-01-15 23:31

    D21a-7 I checked the old transmission screen, the black stuff is definitely not magnetic. Lots of small tiny flakes are clogging up the screen. If I only had a CSI NY kit I could figure out what this material make up consist of? Was just hoping someone, somewhere, had a similar issue with this model dozer.

  8. #8g_man2013-01-16 17:13

    You might want to check out this thread. There is a lot of info on your machine. I seem to recall a similar one to your problem. You might even post your problem there. Is it clutch material ? HeavyEquipmentForums

  9. #9clemonsk2013-01-17 22:41

    D21a-7 transmission trouble Thats what I'm thinking. I don't know of any other material besides metal that would be in the transmission, and capable of continually clogging up the screen. If this is the case, does it mean the transmission will soon be shot? If so, can the clutches in the transmission be replaced?