New Holland TRANS 81 – Transmission Controller (TRANS module): Transmission clutches are slipping

The transmission controller detects that the transmission output speed is too low for the specific gear that is currently selected.

• TG210
• TG215
• TG230
• TG245
• TG255
• TG275
• TG285
• TG305
• T8010
• T8020
• T8030
• T8040
• T8050
• T8.xxx Series
• TJ / T9000 Series

1. 1

   Clear the fault code and engage each gear to determine if the fault reoccurs, noting any abnormal noise or sluggish gear engagement.

2. 2

   Check the Transmission Output Speed Sensor (Wheel Speed Sensor) signal. With key ON and stationary, it should read ~2.5 V DC and ~0 V AC. When moving, AC voltage should increase with speed.

3. 3

   Inspect the wiring from the wheel speed sensor to the transmission controller for shorts, loose connectors, or bent pins.

4. 4

   Verify that the transmission hydraulic pressure is within specification, as low system pressure will cause clutches to slip.

5. 5

   Operate the tractor in all gears to identify exactly which gears are affected, helping to isolate the specific clutch pack or sticking solenoid.

1. 1

   Sensor Replacement/Adjustment

   If the speed sensor fails the voltage test, replace the sensor. If the sensor readings are erratic, the speed pick-up ring may be out of tolerance. Remove the coupling flange and speed ring assembly, and correct the run-out using a lathe (or replace the flange and ring).

2. 2

   Solenoid Inspection

   If the issue is isolated to a specific gear/clutch, check the identified faulty clutch solenoid connector. Ensure it is connected, not damaged, the pins are in the correct position, and the fit is tight. Replace the solenoid if it is mechanically sticking.

3. 3

   Hydraulic Repair

   If system pressure is low, diagnose and repair the transmission hydraulic pump or system pressure valve.

4. 4

   Clutch Pack Replacement

   If the sensor, solenoids, and system pressure are all normal, the fault is caused by a leaking transmission clutch or a failed master/inching clutch. The transmission will need to be split to rebuild or replace the damaged clutch pack.

5. 5

   Calibration

   After any repair, the transmission controller must be recalibrated. Ensure the transmission oil is warmed to more than 60°C (140°F) before initiating the calibration sequence.