downshifting

[refriedbeancounter]

My 94 GT conv will suddenly downshift when I am driving steady. It usually happens on the freeway or on coast highway doing about 50 to 70 MPH. It seems like it's the computer that kicks it down and then slams it back into OD. Any ideas what I should check first?

[04S/CStallion]

Make sure that the brake pedal is coming up all the way. Usually if you keep you foot on the gas at a steady constant rate while cruising and tap the brakes lightly the computer will unlock the torque converter, for a short while and then it will lock back up into OD.

[refriedbeancounter]

It's not that. My car will down shift. The revs jump way up and then it will eventually slam back into OD.

[04S/CStallion]

Sounds like it could be as simple as having the computer reflashed

[refriedbeancounter]

That sounds like it could be it. How do I do that?

[04S/CStallion]

Honestly the only ways I can think of is a ford dealership or a perfromance shop that has a mod mustang edit program.

[mustardjohn]

I had a '94 T-Bird that did that. It was something relatively inexpensive. Not the transmission proper but some electronic part on the outside of the trans. Mine would not do it until the car got hot say after 30-40 miles or so. That made it difficult to trouble shoot. Would never do it when I would take to a repair shop. Had to be hot. It was a real problem like it would jump out of gear then when you let off the gas the rpms would come down and it would reingage. Hard to trust a car like that when you want to pass on a two lane road.

[04S/CStallion]

Come to think of it, my moms stealth did the same thing as ur T-Bird and it was some sensor on the tranny. Can't remember what it was called though. I wanna say it was a govenor switch.

[mustardjohn]

I would not go to the dealership. I did that with the 94 T-Bird and they convinced me that the transmision needed a rebuild. It had about 110K miles on so I did that and it did not fix the problem.

I would recommend a very experienced transmission place that is less interested in billing hours and parts and more interested in a challenging problem. That is who finally fixed my problem. It may have needed a transmission rebuild but that was NOT the problem.

Wish I could remember the part that fixed it. It was electronic and it took the trans being good and hot to make the electronic part begin to fail intermittently. As long as I stayed around the house it worked fine but let me head out to Houston and about 40-50 miles later the fun began. A real pain when you are trying to make the airport for a flight and aren't sure you are going to get there. It never completely failed though and that was the good news.

[Capri306]

If it's on the outside of the transmission, I would venture to say a vehicle speed sensor could be the problem. I'm not entirely sure on an AOD-E that there's not hydraulic pressure sensors or anything of that sort (I just haven't had the luxury of having to deal with one), though. Sounds like a problem that might be in a technical service bulletin somewhere, since a few of you have it. Maybe worth looking into???

[mustardjohn]

Capri306, how do you serch the service bulletins? Can you do that on line? I did a little looking found a site or two but is there a Ford site or some "official" place to look?

I looked under 1994 T-Bird on this site
mycarstats.com

Found a few bulletins on the power train but nothing that looked like the problem being discussed. the ones below were the most promising

TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 96714

MFG Bulletin Date: 960301

Component: POWER TRAIN

Details: SUBJECT REGARDING A NEW TRANSMISSION CASE AND MAIN CONTROL RELEASED FOR SERVICE ON AODE / 4R70W TRANSMISSIONS.

MCS Check Date: 20020528

TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 9943

MFG Bulletin Date: 19990308

Component: POWER TRAIN

Details: INFORMATION REGARDING REPROGRAMMING POWERTRAIN CONTROL MODULES (PCMS). *TT

MCS Check Date: 19990511

TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: BC0678961025

MFG Bulletin Date: 19961025

Component: POWER TRAIN:MANUAL TRANSMISSION

Details: INFORMATION ON AODE/4R7W TRANSMISSION MAIN CONTROL & CASE REPLACEMENT. *TT

MCS Check Date: 19970424

TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 95313

MFG Bulletin Date: 950201

Component: POWER TRAIN:TRANSMISSION:AUTOMATIC

Details: POSSIBLE WATER INTRUSION IN THE MLP/TR SENSOR CAUSING SHIFT CONCERN.

MCS Check Date: 20020528

TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 94269

MFG Bulletin Date: 941201

Component: POWER TRAIN:TRANSMISSION:AUTOMATIC

Details: DELAYED OR NO FORWARD ENGAGEMENT OF TRANSMISSION.

MCS Check Date: 20020528

[refriedbeancounter]

Wow, it sounds like my problem exactly. Is there any way you could contact the tranny shop to find out what it was. I know I am asking a big favor. Thanks for your input.

[mustardjohn]

I will try calling but has been about 3 years and I sold the car since. I am hoping someone on this site will have some more ideas. The speed sensor and the governor were good shots. Wish I knew more about transmissions. Do know my problem was not "in" the trans but "on" it. And it was a 1994 Ford AOD-E which I bet is the same one that is in your 1994 GT.

Taking the car out of OD with the manual button also did not help. So it was not like it was the OD that was causing the problem.

What would just make the clutch disengage? What sensor could throw the car into neutral? Probably not a lot of things that could do that.