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310J SN T0310JX150036 – No 2nd & 3rd gears forward

Joeyinstx · 2025-02-26 07:32

Good Day, Can anybody weigh in on diagnosing my loss of 2nd & 3rd gears (forward) for a 310J. Reverse works fine in 2nd and 3rd. So far I've tested and verified solenoids Y2 & Y3 as working on the bench. Verified and tested the gear selector as working. In the service menu in the solenoid diagnostic mode Y2 & Y3 indicates off even when 2nd and 3rd is selected in the forward on the gear selector. Y2 & Y3 indicates on when selected in reverse. Any ideas on figuring out what is wrong would be greatly appreciated. Thanks

Replies9
  1. #1Diesel Dave2025-02-26 12:00

    The 310J transmission in reverse limits speed selection to only 1st and 2nd . Y1 is the forward solenoid. Y2 is the reverse solenoid. Y3 is the 1st speed solenoid . Y4 is the 2nd speed solenoid. Y5 is the 3rd speed solenoid. Just to confirm , the only transmission issue you are having is no 2nd and 3rd speed in forward ? Double check the service diagnostic menu for the solenoid status.

  2. #2Joeyinstx2025-02-27 06:13

    Yes, correct no forward in 2nd and 3rd. I will check the status of the service diagnostic status for the selenoids again. Thanks.

  3. #3Diesel Dave2025-02-27 08:59

    Find a screenshot below of the clutch engagement and the powered solenoids chart from the ZF WG90 tech manual. .

  4. #4Joeyinstx2025-02-27 09:09

    Hello All, Thanks for the input thus far. This is the result from the diagnostics service menu for the selenoids. Please let me know if this helps narrow down the issue.

  5. #5Joeyinstx2025-02-27 09:23

    thank you very helpful diagram

  6. #6Diesel Dave2025-02-27 09:28

    Based on your findings vs the chart I posted above. In Forward 2nd speed, the Y3 solenoid needs to be powered “on“ ..you found it Y3 solenoid powered “off“ . Apart from Forward 2nd speed all your other solenoid findings agree with the chart.

  7. #7Simon C2025-02-27 09:35

    See the exact same thing when I looked at top chart you posted. Now he knows where to start looking. Simon C

  8. #8Diesel Dave2025-02-27 09:40

    @Joeyinstx ,Correct me if I’m wrong,but from the solenoids that are currently powered on ,the transmission should operate in Forward 4th gear when the gear selector handle is in either 2 or 4.

  9. #9Simon C2025-02-27 09:44

    Thats what I see on the chart also, gear 2 has one more solenoid than gear 4. Simon C