Lincoln Navigator: Automatic Transmission - 10-Speed Automatic Transmission – 10R80 / Special Testing Procedures. Diagnosis and Testing

Line Pressure Test

This test verifies the line pressure is within specification.

1. If available, refer to the Transmission Line Pressure Test general procedure to access the line pressure tap.
   

1. If equipped, remove the heat shield.
   
   1. Remove the 2 bolts. Torque: 10 Nm (88 lb-in)
      
   1. Remove the push pin and the heat shield.
      

1. Connect the transmission fluid pressure gauge (307-004) to the line pressure tap using an M10 X 1.00 fitting.
   

NOTE: The line pressure tap is an M10 X 1.00 thread. Do not use a National Pipe Thread (NPT) fitting when installing a pressure gauge. If a NPT fitting is used, damage to the transmission case will occur.

NOTE: 10R80 shown, 10R60 similar

1. Start the engine and check the line pressure.
   

1. Using a diagnostic scan tool, monitor and compare the PID LINEDSD# to actual measured pressure. Actual measured pressure should be within 10 PSI (69 kPa) of PID LINEDSD#. Raise engine RPM to 2000 RPM and verify LPC operation by monitoring line pressure while commanding LINEDSD# up and down.
   

1. If the line pressure is not within specification, see the Line Pressure Diagnosis Chart for possible sources.
   

1. When the pressure tests are complete, install the line pressure tap plug.
   
   • Tighten to 11 Nm (97 lb-in).
     

  Line Pressure Diagnosis Chart

A no-drive condition can exist even with correct transmission fluid pressure because of inoperative clutches. Refer to the Clutch Application Chart to determine which clutch is applied in each gear range. A clutch concern can be further diagnosed by performing the air pressure test.

Stall Speed Test

NOTE: Carry out the Line Pressure Test prior to the Stall Speed Test. If line pressure is low, do not carry out the stall test or additional transmission damage will occur. Do not maintain Wide Open Throttle (WOT) in any gear range for more than 5 seconds.

NOTE: If the engine speed exceeds maximum specified rpm, release the accelerator pedal immediately.

NOTE: Only perform the stall speed test with the engine and transmission at normal operating temperatures.

To prevent damage to transmission and driveline components, the PCM will truncate engine torque output when a stall condition exists. Because of this torque truncation, the stall test cannot be used as a diagnostic test for determining the health of the transmission clutches.

The PCM monitors clutch performance and will set one or more DTC s when an undesired slip is detected.

The torque converter stator one-way clutch should hold at idle and during acceleration. A failed one-way clutch can be identified if all of the following conditions/symptoms exist:

• Transmission fluid is clean and free of excessive contamination
• Normal/expected vehicle performance at cruising speed
• Poor engine idle quality. The engine may even stall
• Very poor acceleration/Lack of power
• Very low stall RPM: <1500 RPM. Perform test procedure below:

1. Apply the parking brake.
   

1. Connect the scan tool. Navigate to Datalogger: PCM
   

1. Monitor the PID s: APP (%), RPM, LOAD (%) and GEAR_CMD
   

1. Start the engine.
   

1. Place the transmission in reverse.
   

1. Start datalogger recording.
   

1. With the brake pedal firmly applied, press the accelerator pedal to 100% for 2-3 seconds until engine RPM stabilizes. Release the accelerator pedal.
   

1. Place the transmission in neutral.
   

1. Press the accelerator pedal to maintain 1500 RPM for 10 seconds to allow the torque converter to cool. Release the accelerator pedal.
   

1. Place the transmission in drive.
   

1. With the brake pedal firmly applied, press the accelerator pedal to 100% for 2-3 seconds until engine RPM stabilizes. Release the accelerator pedal.
   

1. Place the transmission in neutral.
   

1. Press the accelerator pedal to maintain 1500 RPM for 10 seconds to allow the torque converter to cool. Release the accelerator pedal.
   

1. Turn the engine off.
   

1. Review the recording. A properly functioning stator one-way clutch should fall within the following parameters:
   
   • APP = 100%
     
   • RPM > 1500
     
   • LOAD < 100%
     
   • GEAR_CMD = Reverse or 1st Gear commanded
     

Air Pressure Test

  10R60/10R80 Air Ports

1. Using a high volume rubber tipped blow gun, apply air pressure to the suspect clutch port for 2-3 seconds.
   

1. While applying air pressure, a dull thud on clutches A and B would indicate the clutch piston is applied.
   

1. While applying air pressure, a hissing noise may indicate a leak in the hydraulic passages.
   

1. While applying air pressure, cross leakage in the hydraulic circuit between the C, D, E and F rotating clutch seals is expected.