Transmission Direct Drive slipping/barely engaging

Hi,

If the fluid is clean and full, I would check the transmission line pressure to see if it is dropping when warm. The cooler could be partially plugged, and I've even seen the filter pick up enough dirt from the pan to cause issues. When cold, dirt would drop to the bottom and allow fluid to flow easily. After driving, the dirt would partially plug the filter lowering pressure.

So, before making any decisions, I would either remove the pan and check to make sure it is clean or check line pressure when the problem exists.

Here are the directions for testing line pressure as well as diagnostic charts:

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2001 Ford Truck Explorer Sport Trac 4WD V6-245 4.0L SOHC VIN K SFI
Line Pressure Test
Vehicle Transmission and Drivetrain Automatic Transmission/Transaxle Testing and Inspection Component Tests and General Diagnostics 5R55E Automatic Transmission Line Pressure Test
LINE PRESSURE TEST
Line Pressure Test

CAUTION: Carry out Line Pressure Test prior to carrying out Stall Speed Test. If line pressure is low at stall, do not carry out Stall Speed Test or further transmission damage will occur. Do not maintain wide open throttle in any gear range for more than five seconds.

NOTE: Certain sensor failures may cause high EPC, FMEM (Failure Mode Effect Management) actions. Be sure that self test and electrical repairs have been carried out, or test results may be incorrect.

This test verifies that the line pressure is within specifications.

Pic 1

1. Connect pressure gauge to the line pressure tap on the transmission and a tachometer to the engine.
2. Start the engine, increase and maintain 1,000 engine rpm and check line pressures.

Pic 2

Line Pressure Chart

NOTE: Prior to using this chart, you should check the transmission identification tag. Some early built units will use a different specification.

Pic 3

3. If line pressure is not within specifications, check EPC pressure.
4. Connect Pressure Gauge to EPC pressure tap.
5. Start the engine, increase and maintain 1,000 engine rpm and check EPC pressure. See the line pressure chart for specification.
6. If EPC pressure is not within specification, GO to PINPOINT TEST E to diagnose EPC operation. If EPC operation is OK, see the line pressure diagnosis chart for line pressure concern causes.

Pic 4

pic 5

Let me know if this helps.

Joe

Hi,

Yes, it will cause them to fail quicker. They are designed to go in one direction.

Joe

Hi,

You are very welcome. Also, I think you are right with your diagnosis. There shouldn't have been that much material in the pan. Something burned up. Ugh! Nothing is ever easy.

Take care of yourself and let us know if we can help in the future.

Joe