I have a 2004 Lincoln Navigator 4WD 5.4L V8 with the 4r100 trans in it. I have had harsh shifting into 2rd-3rd which I thought could be due to the transmission being overfilled, from the previous owner, and the “shift solinoid B” engine code. I drained the trans pan and put the correct fluid capacity (5-6 quarts) of Mercon V and replaced the shift solenoid pack. The car is shifting smoother into 1st-2nd gear, but is not wanting to shift into 3rd or 4th gear now. The car does not have any codes, and if you drive the car for a while the overdrive light will start to flash.


Goes into park, reverse, 1st gear, and 2nd gear just fine. Just don’t know why it’s not going into 3rd or 4th gear anymore. My current thought is either the trans input/out speed sensor or the 2-3 shift valve within the valve body.

Anyone have any other thoughts before I drop the pan again.

 

What kind of code reader are you trying? If the OD is flashing, there must be a code......

 

so I scanned it again and it is now showing code P1744 - torque converter solinoid circuit performance. I know the P1744 is a fairly generic code and could mean anything. Got any ideas on where I should start?

 

Look at the electrical connection.
An open electrical circuit to ground?

My F150 needed new front wheel bearings to update and shut off the Lights on the Dash.
No cruise control, anti-skid, Braking that sort of lights.
Most likely the 2 bearing weren't synchronized with the Puter.

Can you hear buzzing sound with everything shut off and driving say 65 mph.
Those bearings are tough, hard to replace and a PITA. You sound like a handy guy.

Once I replaced my front bearings it connected WiFi 2016 F150 and downloaded the update.
Even the stop / start at stop lights started working in Sport Mode.
Those all 4 wheel bearings can really mess stuff up with count of revolutions faulty.

Anti-skid control, traction control, cruise control, engine stop starts all that stuff goes out. No Codes many times.
If you have 130,000 / 200,000 miles on the O most assuredly you got faulty bearings if you never changed them, but still they may have faults now.
Brgs usually fail in that range but sometimes the new aren't so good!

Remove the Brake off the Rotor and get a stethoscope to listen to the wheel bearings when you spin it. It may not feel rough when spinning it. You can hear it.
Rule of thumb replaces both in front first.

My immediate thought is a lot of the crap on vehicles today are a PITA. The fun of working on the 60 / 70's muscles have been ruined.
A Doc. with a meter and Stethoscopes now more than likely.
Back in the day I was working on Yale Material Handling Equipment and would plug them into the puter so Yale could trouble shoot, and update them.
Their most pressing problem was intake valves stems clogging with carbon when running LP. about every 4000 hours on the meters. 80 Leased trucks needing valve jobs a year.

 

I will be checking the wiring this weekends and possibly redoing the connector that leads to the shift solinoid pack.
With the wheel bearings I don’t see that being the cause since I now have an engine code P1744.

 

Sounds good, my thoughts are with synchronization of the bearings RPM and the Putter.
That will screw up lots of stuff. Note how the speeds gear shifts happen at specific miles per hour.
U can probably remove the Solenoid and see if it works by energizing it.

OBDII Ford Code Definitions. Be sure to double check the codes.
Anything P1000 to P1999 or P3000 to P3400 will be Manufacturer
specific and may not match the ones listed here. Check specific
manufacturer pages on the site, as some of them, we list the OBD2
codes on those pages for those specific vehicles.

Even My Wifes KIA Sorento's rear wheel bearing screw up her computer,
Synchrony problems Shut off important stuff, & check motor stuff in the dash lights up.

If I was 19 years old I would take it to a Neighborhood trans shop and talk with the guy I know well.. about it.

 

Looks like it’s all fixed!!

Since it all started having the shift issue after I had drained the trans pan only, I leaned towards not the correct level or I didn’t add the fluid correctly.

I ended up draining the trans pan only and put new fluid back in. The only difference I did this time was running the car up in the air and running through all gears until the car gets to running temp.

Last time I didn’t run it until operating temps so maybe that was my mistake.

 

I had the same issue in my 2002 F350 with 4R100. The transmission worked perfectly in park, first, second and reverse. We changed the accumulator valve body and the problem was resolved. Less than $500 repair.