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Terex TA40 gearshift problems

Discussion in 'Other Earthmoving Equipment' started by kevman6, Jun 24, 2017.

  1. kevman6

    kevman6 Member

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    We have a 2002 TA40 that won't move forward. Seems to be bound between forward and reverse. Reverse works great, neutral fine. No brakes locked up. All pressures to the gearshift valve body check out at 220-230 psi in the proper solenoids for each gear. Backed up to dump a load, and wouldn't go forward. Can only think its inside the gearshift assembly. Any input would be appreciated greatly. Also anyone know of a rebuilt for these available. Does not appear to be a clutch lock up, because of all the correct pressure in proper solenoids. No reverse pressure when in forward gears at F, or Y1
     
  2. GaryHoff

    GaryHoff Senior Member

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    ZF or Allison transmission? I believe this year has the zf transmission.
    If all your reverse gears are working, your transmission is likely physically ok. Is there any fault codes active?
    Sometimes the wires break off at the shifter lever, or the lever can fail. Usually the top button is the one that fails.
     
  3. kevman6

    kevman6 Member

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    This is a ZF trans. No codes, when in F2 is locked with forward and reverse. Reverse and neutral work fine. All pressure at the valve assy are proper, no pressure where it shouldn't be. Disconnected the hoses to reverse (Y1,and Y3) and capped them at the valve assembly, no longer goes into reverse, so it shouldn't be locked at clutches, but still will not pull forward now because we have the second hose (Y3) that would assist forard 2 also assists reverse 1 and is capped. But it is not locked between two gears now, just wont go forward, like not enough power, or in neutral. I have the valve assembly on the bench now and disassembled. No visual problems with valves or springs. Waiting for gaskets for reassembly. Electrical problem would certainly be easier to fix if I can find it. And suggestions certainly are a help. Shift lever shifts through all the gears according to the dash and pressure gauges getting the proper routing pressures while shifting through all gear selections. Also, the bed was up and trying to move forward when this happened.
     
    Last edited: Jul 6, 2017
  4. GaryHoff

    GaryHoff Senior Member

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    When the box is up, you are limited to F2 as max gear. Any other lights on in the dash?

    Sounds like you have a service manual, and have looked at the shift logic. It also sounds like the transmission valve was working properly. Transmission valve is usually not a issue.

    I have had where the axles break the splines off, usually on the front diff. Turn on all your diff locks, and see if it moves.

    Does it pass a transmission calibration?

    Just verifying the gears that still work:
    R3 ok
    R2, ok
    R1, ok
    N, ok
    F1, not ok
    F2, not ok
    F3, not ok
    F4, not ok
    F5, not ok
    F6, not ok
     
    Last edited: Jul 7, 2017
  5. kevman6

    kevman6 Member

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    Yes, all reverse and neutral are working. all forward gears attempt to go into reverse, and then lock up. At one point it would even move backwards while in F2, then when I shifted back to N and then back to F2 it locked up again. I am waiting on valve gaskets to put assembly back together. It made no difference with the diff lock on or off, and even tried it unplugged. I do not have the tool for trans calibration. No other lights are on.
     
    Last edited: Jul 7, 2017
  6. kevman6

    kevman6 Member

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    It also tows forward in neutral just fine. We moved it to a better location without a problem
     
  7. Bigbert

    Bigbert Well-Known Member

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    I'm afraid you need a repair on KR clutch. The behaviour of your truck looks very much like warped KR clutch discs.
     
  8. GaryHoff

    GaryHoff Senior Member

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    +1 on KR clutch.
    Do a transmission calibration to verify. Your local Case dealer can connect to the transmission, and calibrate it, using the case wheel loader adaptor cable, and selecting the Case rock truck as the model. Or anyone that is a ZF dealer or has the software could connect too. The calibration should fail at clutch KR.

    The AEB starter is cheap, so you could just get one yourself just to calibrate the transmission.
     
  9. Bigbert

    Bigbert Well-Known Member

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    Great ideal.
    Any deere Case terex moxy doosan Hyundai dealer should be able to run clutch calibration.
    Please also check oil for burnt smell and debris in oil and filter.
    No fault Code "BA" active on display at operating temparatur? (polluted filter)
     
  10. kevman6

    kevman6 Member

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    There are no codes. Put the valve body back together, now goes into reverse when in F2, reverse works fine and neutral works fine.
    Shifter continuity checks good. Going to put all six gauges on valve body today again to recheck pressures. I will have to check where AEB starter is available from.
     
  11. kevman6

    kevman6 Member

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    Rechecked pressures today after the rebuilt valve assembly was reinstalled. Yesterday it would back up in Forward gears, today it doesn't. Today it just lockes up when in forward gears. Pressures are all where the should be in Y1, Y2, Y3, Y4, Y5, Y6 for each gear selected in both forward and reverse. We capped off KR and K1. This eliminated the any movement when selecting reverse R1 as it should, but still wouldn't allow forward movement in F4 which doesn't use those valves. I'm wondering if the converter is not getting pressure in forward gears. I will check converter pressures tomorrow at WK. I didn't have any today, but still had a few valves and hoses capped. Driving me crazy trying to figure this out. Still have not done an AEB calibration. Have to find someone who can do it still.
     
  12. GaryHoff

    GaryHoff Senior Member

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    The ZF transmissions are just poor design for this size of truck. They don't hold up. That's why Terex switched to Allison transmissions in the 40 tonns, and have had way less issues.
    I`m with BigBert, on the KR clutch. If your moving reverse when in forwards gears, the KR clutch is stuck on from being warped.
    I usually see the clutches slipping, not warping. But since you don't have a AEB starter, you likely haven't calibrated your transmission in a LONG time. Everyone who has these transmissions calibrates them at least every week, and has their own AEB starter. Lack of calibrations leads to early failures. You can buy a AEB starter from Terex or a ZF dealer.

    Might be hard to find a terex or moxy dealer these days. I cant verify that deere, Doosan or Hyundai can do the calibration. I know for sure the Case will work :). Can also monitor the shaft speed sensors with the Case software too.

    I`ve heard that you can do the clutch calibration by jumping the pins together at the AEB connector under the dash, then disconnecting and connect to continue the steps. I haven't personally tried it, so not sure if it actually works or not.
     
    Last edited: Jul 12, 2017
  13. kevman6

    kevman6 Member

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    If KR clutch is locked or warped, why then would it not still move in reverse when KR and K1 pressure hose is capped, and R1 is selected. Wouldn't that test for a mechanical lockup? We have only had this truck a couple months, and just have all the records for it from the past, which includes a new trans two years ago. Since we have purchased it , we have put less then 20 miles on it. We are just using it to dig a pond, and move the dirt to the other side of the property.
     
    Last edited: Jul 12, 2017
  14. Bigbert

    Bigbert Well-Known Member

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    Hi Kevman,

    a ZF tranny WG type (here 6WG310) needs two clutches to create drive. So if you cap KR and K1 there is are two clutches disengaged. With KR warped there is still K1 which avoids drive. So (in R1) please only cap KR, keep K1 pressurized and I assume the truck will move reverse in R1.
    Oil is clean? No smell?
    AEB starter: All OEM's with ZF transmissions (Ergopower) use same type. So any Deere, CNH, Doosan, Hyundai, Terex, Moxy dealer/workshop should be able to provide that tool.
    But please run the test R1: KR capped, K1 with pressure. What is truck doing?
     
  15. kevman6

    kevman6 Member

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    Truck still went into reverse with KR capped and all other clutches connected. I'm assuming reverse clutch is locked. Any idea what usually causes this and what to expect if we go inside. I'm quite sure it's not just a clutch and plate service, seeing that it's locked up. Have to decide if it's worth the effort and money. Great truck, everything works and is tight, (except trans :( ), even the AC.
     
  16. Bigbert

    Bigbert Well-Known Member

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    Frankly speaking I expected this behaviour of truck.
    The condition of oil might tell you something about condition of discs and carrier.
    Usually "only" the discs (steel and friction discs) are gone and need to be replaced, possibly the piston seal rings.
    There carrier might show some heat marks, but should be re-usable. Bearings should be ok, however K1 bearing needs to be replaced as it will be damaged during disassembly.
    There is very very low risk for further damages, no gears or so.

    The labour for removal, disassembly, cleaning, assembly is the costdriver.
    Make sure the workshop fit the correct discs in KR, correct ZF no. These are different to the other clutches of t/m.
    Any serial number and parts list no. available?
     
  17. kevman6

    kevman6 Member

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    I have ordered an AEB starter, just waiting for its arrival from the UK. Is it worth waiting to see if calibration will cure the problem, or is that not possible it could be that far off?
     
  18. Bigbert

    Bigbert Well-Known Member

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    Wait until you can run the clutch calibration.
    Guess, it will throw a code on KR. AEB starts on K1, K2, K3, K4, KV (F), then KR.
    The AEB is not able to cure anything, it is only supposed to adjust the correct filling of the clutches.
    If some KR discs are warped the AEB will not find appropriate values and show a code on display.
    I doubt correct filling pressure will solve your issue, but never give up hope.

    For AEB heat up t/m oil to more than 70 degrees C, apply parkbrake, run engine with approx. 800 - 1000 rpm.
     
  19. kevman6

    kevman6 Member

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    been a while coming, but KR was burned along with clutch at other end of that shaft. everything looked good. running good.
    get an occasional fault when shifting manually. maybe trying to run to high of gear at too low of RPM
     
    Bigbert likes this.
  20. Bigbert

    Bigbert Well-Known Member

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    Thanks for Info.
    TCU does not allow too high gears at low Input speed to protect t/m from overheating.