Case IH U44 – Transmission Control Unit (TCU) or Chassis Control Module (CCM): Synchroniser did not move toward 5, even at max pressure.

The transmission control system commanded a shift into the 5th gear position and applied maximum hydraulic pressure, but the position sensor (potentiometer) failed to detect the synchroniser physically moving into the correct position.

• Maxxum
• Puma
• MX170
• Farmall
• JX / JXU

1. 1

   Swap the electrical connectors for the 4 and 5 solenoids (or the 1-4 and 5-8 synchroniser solenoids) to see if the fault code changes, indicating a faulty solenoid.

2. 2

   Check the signal voltage of the synchroniser potentiometer using the H9 diagnostic screen or a voltmeter, comparing it to a known good sensor.

3. 3

   Visually inspect the synchroniser potentiometer and its connector for damage or accidental factory paint causing grounding issues.

4. 4

   Verify that there is sufficient hydraulic oil pressure reaching the valve block to physically shift the synchroniser.

5. 5

   Remove the transmission top cover and physically watch the synchroniser movement while the tractor is running to detect mechanical binding or fork movement issues.

1. 1

   Clean the area around the transmission top cover to prevent contamination.

   Clean the area around the transmission top cover to prevent contamination.

2. 2

   Disconnect the hydraulic oil supply tube.

   Disconnect the hydraulic oil supply tube.

3. 3

   Remove the transmission top cover retaining bolts and carefully lift off the transmission top cover.

   Remove the transmission top cover retaining bolts and carefully lift off the transmission top cover.

4. 4

   Inspect the 5-8 synchroniser assembly and shift forks for wear, stickiness, or damage.

   Inspect the 5-8 synchroniser assembly and shift forks for wear, stickiness, or damage.

5. 5

   If replacing the sensor: Remove the faulty synchroniser position potentiometer and install the new sensor.

   If replacing the sensor: Remove the faulty synchroniser position potentiometer and install the new sensor.

6. 6

   If replacing the solenoid: Remove the faulty C1/C2/C3 PWM solenoid and valve assembly.

   If replacing the solenoid: Remove the faulty C1/C2/C3 PWM solenoid and valve assembly.

7. 7

   Coat all new valve components and the synchroniser with clean transmission oil (Case IH Akcela Nexplore™ Fluid) prior to assembly.

   Coat all new valve components and the synchroniser with clean transmission oil (Case IH Akcela Nexplore™ Fluid) prior to assembly.

8. 8

   Reinstall the transmission top cover and tighten the retaining bolts to a torque value of 27 Nm.

   Reinstall the transmission top cover and tighten the retaining bolts to a torque value of 27 Nm.

9. 9

   Reconnect the hydraulic oil supply tube.

   Reconnect the hydraulic oil supply tube.

10. 10

    Perform a full transmission calibration procedure so the control module can learn the new synchroniser and sensor values.

    Perform a full transmission calibration procedure so the control module can learn the new synchroniser and sensor values.