Massey Ferguson 6.X.4E – Rear Linkage / Hitch Controller: Rear PTO end-fitting: The number of splines on the speed sensor PTO output shaft is not compatible with the speed of 1000 rpm.

This code triggers when the operator selects 1000 RPM PTO speed in the cab, but the sensor (X776) detects that the 6-spline (540 RPM) stub shaft is currently installed, or the sensor is failing to read the 21-spline shaft correctly.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4700 Series
• 4707
• 4708
• 4709
• 4710
• 5700 Series
• 6700 Series
• 6711
• 6712
• 6713

1. 1

   Physically count the splines on the rear PTO stub shaft (6 splines = 540 RPM, 21 splines = 1000 RPM)

2. 2

   Verify the PTO speed selector switch in the cab matches the physical shaft installed

3. 3

   If the correct 21-spline shaft is installed, inspect the wiring harness and connector for the X776 Rear PTO end-fitting speed sensor for corrosion, chafing, or loose connections

4. 4

   Remove the PTO stub shaft and inspect the internal sensor target area for excessive wear, metal shavings, or debris blinding the magnetic speed sensor

1. 1

   Prepare tractor for shaft replacement

   Scenario A (Incorrect Shaft Installed): Ensure the tractor is turned off and the PTO is disengaged.

2. 2

   Locate retaining mechanism

   Locate the retaining mechanism for the PTO stub shaft. Depending on the exact model, this will either be a heavy-duty snap ring (circlip) around the base of the shaft, or a flange held in by bolts (commonly 4 bolts).

3. 3

   Remove retaining mechanism

   Remove the snap ring using circlip pliers (or unbolt the flange).

4. 4

   Remove incorrect shaft

   Pull the incorrect PTO stub shaft straight out of the rear axle housing. (Note: The shaft is housed inside a tube, so oil loss should be negligible, but have a rag ready).

5. 5

   Prepare correct shaft

   Clean the splines of the correct 21-spline (1000 RPM) shaft and apply a thin coat of clean grease or anti-seize compound.

6. 6

   Install correct shaft

   Slide the new shaft into the housing, rotating it slightly to align the internal splines.

7. 7

   Secure shaft

   Reinstall the retaining snap ring or flange bolts securely.

8. 8

   Locate speed sensor

   Scenario B (Faulty X776 Sensor - Correct shaft is already installed): Locate the X776 speed sensor on the rear PTO housing.

9. 9

   Disconnect sensor harness

   Disconnect the electrical harness from the sensor.

10. 10

    Remove faulty sensor

    Unthread the faulty sensor from the housing.

11. 11

    Install replacement sensor

    Install the replacement sensor and torque to OEM specifications.

12. 12

    Reconnect and test

    Reconnect the wiring harness, clear the fault codes via the diagnostic menu, and test PTO engagement.