Massey Ferguson 04.00.B1 – Transmission Controller (TRANS) / Autotronic 4 or 5: Transmission Range Change Issue (TRANS)

Occurs on tractors equipped with the Dyna-VT continuously variable transmission. Triggered when the transmission controller detects an illogical range shift, a calibration error, a sensor value out of tolerance, or a failure to engage the requested range. A common underlying cause is operator error, specifically shifting between the Hare and Tortoise ranges on the fly while under heavy load.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 6600 Series
• 7700 Series
• 8600 Series
• 8700 Series

1. 1

   Operator Interview: Ask the operator if they have been shifting ranges while moving under load, as this bypasses the transmission's safety parameters and causes harsh shifts.

2. 2

   Check Transmission Oil (Mechanical Cause): Inspect the transmission oil level and condition. Look for milky oil, a burnt smell, or excessive metal filings in the oil or filters, which indicate severe mechanical wear of the synchronizer/dog clutch.

3. 3

   Inspect the Range Position Sensor (Electrical Cause): Check the Hare/Tortoise range position sensor (Sensor X17) for correct calibration. Ensure its values are within the specified tolerance ranges.

4. 4

   Test the Solenoid Valve (Electrical Cause): Test the coupler function solenoid valve (Valve X12) and the range change actuator for proper electrical operation and resistance.

5. 5

   Check for Software Issues: Verify if there are internal RAM/EEPROM errors in the TRANS controller, as faulty programming can cause illogical range shift codes.

1. 1

   [Electrical Issue] Locate components

   Locate the range change solenoid valve and position sensor on the transmission hydraulic control block.

2. 2

   [Electrical Issue] Replace faulty component

   Disconnect the wiring harness and replace the faulty solenoid valve or position sensor.

3. 3

   [Electrical Issue] Recalibrate sensor

   Recalibrate the transmission range sensor using the Massey Ferguson/AGCO diagnostic tool.

4. 4

   [Mechanical Issue] Set to Neutral

   Move the range selector (Hare / Tortoise) to the 'Neutral' (middle) position.

5. 5

   [Mechanical Issue] Drain transmission oil

   Unscrew the two closing plugs on the inner surface of the gearbox housing and drain/recover the transmission oil.

6. 6

   [Mechanical Issue] Remove locking screws

   Unscrew the upper M12 locking screw and the two locking screws on the lower shaft.

7. 7

   [Mechanical Issue] Attach lifting tackle

   Attach a lifting tackle to the hydraulic module and apply slight tension.

8. 8

   [Mechanical Issue] Extract suspension shafts

   Using a slide hammer puller on the M20 threads, extract the flexible suspension shafts.

9. 9

   [Mechanical Issue] Extract transmission module

   Carefully extract the Dyna-VT transmission module out of the gearbox housing using the lifting tackle.

10. 10

    [Mechanical Issue] Disassemble and replace parts

    Disassemble the module on a bench to replace the worn range synchronizer and dog clutch.

11. 11

    [Mechanical Issue] Reassemble and refill

    Clean all mating faces, reassemble the module into the housing, and refill with approved transmission fluid.