I did a search and found some help, but didn't find everything I needed. Help! Just pulled my '93 4.0L out of retirement. Has 180K on it. had OD last winter when I drove it, now it doesn't. Did an oil/filter change, gentle flush like the forum suggested and changed the modulator. shifts better, but still no OD. I did have no speedo (digital dash), but cleaned up the sensor and that's good now. Checked all the turn signals and fuses. All appear to be working. I haven't adjusted the bands yet, but it's not slipping, it's just not there. Last winter when I had it on the road for a couple weeks, the wife said it was jumping in and out of OD. So, do I have a 3 speed now, or are there more things to try??????? Thanks.

 

The ECU uses the speedo to determine when the OD should be engaged. If the speed sensor wasn't working, I would think nothing shy of replacing it would give you a clean enough signal to get OD working again.

But just to rule out some possible obvious problems, have you checked to make sure the shifter is aligned properly? If it is out of alignment, then what appears to be OD, may be just regular D.

There are possibility that the solenoid may be failing to energize too. You could test the circuit and see if the OD circuit energizes. To do this you will need some aligator clips to piece the wires, and then hook it up to a digital volt meter. Ge the vehicle up to a speed where the OD should engage. The voltage should jump when the desired speed is reached. If it does, but the OD still hasn't engaged, then either the solenoid is toast, it is jammed, the valve body is leaking, of the OD band is broken.

 

Never thought of the solenoid. Hmmm, I'll have to check that. As for the shift indicator, it hasn't come off first in a few years.
My manual really bites. Where might I find the solenoid????
Thanks.

 

Try and see if it's actually not going into 4th gear (OD) or not locking the torque converter. You can shift between OD and D to check. There is a solenoid to engage the TC lock, and that can be affected by the brake lights (not the turn signals), but I assume you've found those to be are OK. I have heard of these torque converters failing, and losing the lock up capability. In that case, you have no choice but to replace it.

 

The converter is definitely locking. I can shift it manually and get the 3 lower gears. Just not OD. I checked those really obvious things before I asked, but it never hurts to ask. With no slippage, I'm running 3100ish rpm at 60mph. I recall it being a LOT lower than that last winter.
I wasn't sure about the light thing. They all work. Brake and turn.

 

From Ford Service CD

o No 3-4 upshift.

Possible Source(s):
§ 3-4 shift solenoid is not being energized electrically. Wires shorted or an open circuit.
Circuit continuity:
3-4 solenoid wire pin 52 should read approx. 20 ohm resistance.

Action(s) to Take:
§ Perform EEC-IV diagnostic check -- «Key On, Engine Off» . Check circuit continuity with breakout box T83L-50-EEC-IV, and volt ohmmeter. Check power pin no. 57 (red lead) and 3-4 pin 52 (black lead).

Possible Source(s):
§ Transmission case connector and harness connector not seated.

Action(s) to Take:
§ If not seated, check for contamination, clean and reconnect. Perform EEC-IV diagnostic check -- «Key On, Engine Off» .

Possible Source(s):
§ Malfunction of:
-- PCM

-- Throttle position sensor.
-- Vehicle speed sensor.

Action(s) to Take:
§ Perform EEC-IV diagnostic check -- «Key On, Engine Off» .

Possible Source(s):
§ Check O.D. band adjustment.

Action(s) to Take:
§ Reset band to 2.0 turns.

Possible Source(s):
§ Overdrive servo damaged or leaking.

Action(s) to Take:
§ Check cover seal and piston assembly -- replace if required.

Possible Source(s):
§ Polished or glazed overdrive band or drum.

Action(s) to Take:
§ Service or replace.

Possible Source(s):
§ Contaminated or sticking 3-4 shift valve.

Action(s) to Take:
§ Clean or replace valve body. Check 3-4 shift valve for freedom of movement.

Possible Source(s):
§ Contaminated and sticking 3-4 solenoid.

Action(s) to Take:
§ Clean or replace 3-4 solenoid and filter sleeve assembly.

 

WOW! Thanks. Give's me pretty much every possibility.

 

with 3.73 diffs, should see approx 2500 rpm at 60 mph in OD 4th TC locked up

 

That's much closer to what I remember.

 

Sorry to bring this thread back up, but I got thinking and I don't know where the 3-4 shift solenoid is. Any pics or directions would be much appreciated.

 

My A4LD Rebuild Diary - Part 3 - Reassembly - Ford Explorer Ranger Enthusiasts Serious Explorations

http://www.explorerforum.com/forums/...d.php?t=126461

A4LD Valve Body Rebuild Diary - Ford Explorer Ranger Enthusiasts Serious Explorations
Well now we switch sides. SOLENOID TIME. The end solenoid is the torque convertor solenoid (BORE 200 - Torque Convertor Clutch Shuttle Valve)) next one over is the infamous 3-4 shift solenoid (the OD solenoid - BORE 202 - TCC clutch modulator valve) shown in exploded view..

 

OK, so now I have LOTS more info. Where on the outside of the transmission is the harness for the solenoid and which pins do I check????
I never thought to look in the explorer forums. Makes sense though.
Reps sent.

 

Transmission repair manual, A4LD: Bulkpart transmission parts