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

 

[NO BRAKES]

sounds like its time for a rebuild bud

 

[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

 

[CobraRed_96_GT]

Slipping or shuddering is mainly a torque converter problem, doesnt mean the rest of the trans hasn't bit the dust. Hanging shifts or delay then hard shifts is a accumulator thing. Not shifting is more of a clutch-pack gear internals thing and will likely need a rebuild unless it's something simple like a solenoid that's locking it out.

 

[navarro98gt]

Slipping or shuddering is mainly a torque converter problem, doesnt mean the rest of the trans hasn't bit the dust. Hanging shifts or delay then hard shifts is a accumulator thing. .

Exactly what my slushbox does. My converter just started shuddering at low rpm's around 20-25mph's. The shifts also hang then slam into gear. Bah...I dont know if its a smart thing to order a new converter and valve body.

 

[CobraRed_96_GT]

Exactly what my slushbox does. My converter just started shuddering at low rpm's around 20-25mph's. The shifts also hang then slam into gear. Bah...I dont know if its a smart thing to order a new converter and valve body.

Let me guess, just as it shifts into 3rd gear, low rpms, very part throttle? You give it more gass and it goes away by downshifting and then upshifting under more power?
Well low rpms in a high gear is where the most load is, it's like pedaling slow then going to a harder gear.
That's definitly shudder. For now try Mercon V fluid which targets that. if it goes away some or most then your trans will likely be fine with a new TC. As for the hanging shift (usually 1st-2nd right?) it's the accumulator piston/spring which breaks in oem form. With a new valvebody, accumulator replaced to J-mod specs, and a big trans cooler you may be in the clear.

 

[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

 

[jlds91389]

my car is starting to shudder bad. I dont think my fluid and filter have ever been changed and the car has 100k miles. would this be a result from that?

 

[ran260gt]

my car is starting to shudder bad. I dont think my fluid and filter have ever been changed and the car has 100k miles. would this be a result from that?

With all the your mods spent on your Mustang , you never changed your filter/fluid to easy not to do

 

[jlds91389]

ya i know and i be im about to pay for the neglect. the trans is not slipping or anything just shudders real bad. do you think if i drain all the fluid including the tc and put a big cooler on it will help... i sure hope so