4R70W Won't Upshift?

[AdriMagnon]

Hi,

I hope somebody here can help me with this.

I have a 1994 Mercury Cougar 4.6 V8 with the 4R70W and 160,000 miles. The transmission is original and has not been rebuilt.

Yesterday I backed out of a parking spot, stopped, put the car in 'D' and drove off. I heard the engine revving really high and when I looked it was around 3,0000 rpms. I stopped in a parking lot, cycled through the transmission selections several times and drove off. It didn't fix it. So as it stands my car does the following:

* I have only one 'D' gear. In that gear 45mph is about 2600 rpms and 50 mph is about 2900 rpms.

* If I am driving in 'D' and at 45 mph and I shift into '2' or '1' nothing changes. The RPMs don't change and neither does the speed.

* If I press the 'O/D off' button while driving nothing changes. The RPMs don't change and neither does the speed.

* I can still put the car into park, reverse and neutral with no noticeable problems or differences.

I checked the fluid today after she sat overnight and it was at the right levels. It appeared to be the right color and I did not notice any specs of debris in the fluid.

Before this the only problem that I had started about 7 months ago and it was that I would put the car in drive and I would have to rev her up a bit before she'd move. It only happened when she was cold and I had heard about the fluid pressures in the AOD-Es being finicky so I thought nothing of it. I would back out of a spot when she was cold, put her into drive and apply a little throttle and wait a few seconds and then its like the transmission would 'take' and she'd begin to move.
Also for the last two weeks or so I couldn't start my car when it was parked. I'd turn the key and nothing. I would then shift from 'P' to 'N' and back up to 'P' and then I could start my car. Today I had that problem and just to see I started her in 'N.' I turned her off, placed her in 'P' and she started up again.

I have done some checking and think it can be one of four things: EPC Solenoid, Throttle Valve adjustment, Shift linkage adjustment or unfortunately Overdrive band has died.

What do you think it could be? Am I missing something here? I'm really hoping it isn't a costly rebuild I need.

I appreciate any help you can give me.

Thanks,

Adrian

 

[AdriMagnon]

Hi,

I don't know if this makes a difference but I just wanted to add that at no time with this car has the transmission ever slipped.

Thanks,

Adrian

 

[Turdle]

I want to check something please

from a dead stop, place the shifter in 1, then start driving. At about 20 mph, shift to "2" and see if it does indeed shift from 1-2

 

[CDW6212R]

Welcome Adrian, do you know if it is the 4R70W or the AODE? I'm not familiar with all of the carry over changes, and I think the AODE wasn't used for a 4.6 engine.

With that mileage you have many likely possibilities. Most checks or upgrades will help for the future and not be a waste of money. But these may not fix the problem, just help towards rebuild issues.

The valve body is the issue with most shifting problems, and the solenoids and EPC also. You can install a VB kit for about $50 and replace a solenoid or two that may help. I would do that first, and the range sensor. The DTRS range sensor is poorly designed in early models, they don't keep out moisture. An improved version is about $60, check with the several good trans parts suppliers.

The accumulators have been improved by the aftermarket since the trans was made, they are very good to help control fluid leakage. Depending on how much time and money you want to spend, you could do some of these things and possibly get it to work right again. But that's only if you don't drive it at all after it has begun slipping. The slipping will be eating the frictions. That kills everything fast, the debris plugs up the VB and nothing works right. So search around and check parts pricing. See who you may find to do the valve body work etc. Regards,

 

[AdriMagnon]

Hi,

I just wanted to give an update incase anyone has the same problem. I replaced the neutral start safety switch and the up-shifting problems and the car not starting in P or N all went away. I did it about a week and 1/2 ago and have had no problems since. I thought it was weirdest that this wouldn't let the car upshift when driving but who knows the problems electronics can bring.

Thanks,

Adrian