Renostar

Well, I seemed to solve one problem (see my last post "'93 Aerostar hard to start when cold") only to discover another more serious issue: the tranny seems to be slipping when in overdrive. I have the 3.0 liter motor, automatic w/overdrive. Drives fine in every gear except overdrive, feels like it's slipping, most noticeable at highway speed. I'm hoping a band adjustment will fix it. Any ideas or suggestions? Thanks in advance.

Renostar

Bump.

Bert

Ford has issued a TSB on this problem. It has to do with a transmission oil pump defect and repair procedure.
Article No.: 97-22-4
Date: 10/27/97
Transmission - A4LD, 4R44E/4R55E, 5R55E - Torque Converter Slip - Diagnostic Trouble Code (Dtc) 628 Or P0741 Stored In Memory
Ford:
1985 to 1993 Mustang
1987 to 1988 Thunderbird
Lincoln-Mercury:
1988 Cougar
Light Truck:
1985 to 1990 Bronco II
1985 to 1997 Ranger
1987 to 1997 Aerostar
1991 to 1997 Explorer
ISSUE:
Some vehicles may experience excessive torque converter slippage, torque converter not engaging, or Diagnostic Trouble Code (DTC) 628 or P0714 stored in memory. This may be caused by damage to the fluid pump support seal and/or to the groove on the pump where the seal is located.
ACTION:
Inspect the fluid pump seal for damage. Refer to the following Service Procedure for details.
SERVICE PROCEDURE:

1. Follow normal diagnostic procedures as listed in the appropriate Service Manual.
2. Inspect the fluid pump support for damage. If damaged, also inspect the fluid pump support seal groove on the pump.
3. If the groove is damaged, replace the pump.
4. If the groove is not damaged, replace the fluid pump support seal with a redesigned Seal (F77Z-7L323-AA). Refer to Figure 1.
5. Do not replace the torque converter unless it is damaged or fails the criteria listed in the appropriate Service Manual and/or refer to TSB 96-26-12.

__________________
Bert

Renostar

Thanks for taking the time to answer my post Bert. Sounds like an expensive fix (I was afraid of that), and is beyond the scope of my Chilton's, which, other than removal and installation of the tranny and adjustment of the bands and kickdown lever, doesn't cover transmission repair. Do I have to remove the transmission in order to get at the fluid pump? Do I need to get a factory service manual to attempt this repair?

The past couple of days it has stopped slipping when in Overdrive, now it seems that there is little to no difference in engine speed when shifting from Drive to Overdrive, and vice-versa. When I first posted you could really feel it slipping when in Overdrive, almost like it was rapidly alternating back and forth from Drive to Overdrive. Now when I shift from D to OD (and vice-versa) I notice a slight change in RPM, but not much. I'm not too familiar with an automatic tranny with overdrive, so I don't know for sure what is normal, but logic tells me it should be like having an extra gear, and the motor doesn't seem to be dropping in RPM like it should when I'm cruising around on a flat surface in OD. Also, speedometer doesn't work, needle will occasionally vibrate a bit and digital odometer will flash when in motion. Could the two problems be related? The motor and transmission doesn't seem to leak a drop of oil, if that makes any difference. It shifts fine while in drive too, if that also makes any difference. Check engine light comes on occasionally and randomly, usually doesn't stay on for long. Maybe time to get a code reader, eh? If it is the transmission fluid pump, do I risk further damage to the transmission by driving it without fixing? I'd like to take it to a professional mechanic, but I'm very financially challenged, so I can't afford an expensive repair. Suggestions always welcome.

Thanks again kind people for taking the time to offer your advice. This is a great forum.

Bert

Make sure all the vacuum hoses are connected from the manifold. The MAP sensor hose can cause problems too. Does it run good otherwise? Has the transmission been serviced? Sometimes a service will help, but it should be done peiodically to prevent problems from showing up. The light coming on indicates a problem somewhere. They usually can get closer to what problems are there and have them fixed. Engine running problems will affect the transmission shifting. Get the codes and post back. If it is the pump, the transmission does have to come out.

__________________
Bert

Renostar

I'll check to make sure all the vacuum hoses are connected. Engine runs great, was told that motor was replaced with a rebuilt unit at 152,000, and when odometer randomly flashes on/off I can see it's stuck at 162,000 miles, so the motor seems to be okay. Don't know if the transmission has been serviced, previous owner didn't have much information about the service record, but she told me she didn't have any work done to the tranny. Not sure if I should trust check engine light, wiring has been butchered by a previous owner who did a lousy job of installing a stereo system and speakers (which currently does not work). I.E. door ajar light stays on when all doors are firmly shut, and I noticed some wires have been cut coming out of driver's side door. Guess I'll have to buy a code reader to get some definitive answers.

I did take it on a 2 1/2 hour round trip drive to pick up a snowmobile yesterday, and it performed fine, even with a 480 LB snowmobile in the back. I just kept it under 65 MPH in overdrive, and it didn't slip at all, however it doesn't feel like it's shifting into the taller gear unless it's going downhill, and then I can feel a slight shift and a drop in RPM. Engine doesn't seem to be laboring excessively hard otherwise, just doesn't feel like it's shifting into the highest gear when on a level surface. Gas mileage was pretty decent yesterday too. It all seems a bit weird to me. Haven't felt any tranny slippage since that one day that prompted me to start this thread. Check engine light didn't come on until I was 2 minutes from home, and even then it didn't stay on very long.

Thanks again for all the great advice Bert. I'll post an update when I can afford to buy a code reader and see what the computer has to say.