Truck stuck in four wheel drive

1999 FORD EXPEDITION
240,000 MILES • 5.4L • V8 • 4WD • AUTOMATIC
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JAYAR BELISLE
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When in drive/reverse out of a parking spot or make a turn truck makes a humming, clunking, and slows down or stops and have to give it more gas to move. When i drive straight all it does is hum. When i turn the electronic 4x4 knob the 4x4 light turns on and i hear relay clicking.
Apr 6, 2019 at 12:34 PM
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STRAILER
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It sounds like the encoder motor is seized up not tracking correctly. Here is a diagrams so you can remove the motor to see if it is working correctly. Please check it out and get back to me.

Check out the diagrams (below). Please let us know what happens.

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Apr 8, 2019 at 1:13 PM
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JAYAR BELISLE
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I removed the shift motor and the transfer case was already on 2 hi and the video is the shift motor switching AWD to 4 HI to 4 LO back to 4 HI to AWD.
Video (Click to enlarge)
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Apr 9, 2019 at 3:56 AM
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STRAILER
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Thanks for the video, yes that seems to be working fine, can you tell where the noise is coming from?
Apr 9, 2019 at 11:39 AM
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JAYAR BELISLE
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The noise is coming from the front of the truck.
Apr 11, 2019 at 6:12 PM
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STRAILER
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Can you go for a ride and take a video so I can see what is going on?
Apr 12, 2019 at 10:10 AM