4R70W problems.....

95CaliSC

Registered User
Well it looks like my trans is leaking fluid from just about everywhere. Front seal, linkage, output seal and everywhere in between. Ive got a friend to that can help me pull it and reinstall but have been quoted about 300 to reseal it and 1200 to rebuild it. It has 102k miles on it and shifts fine but am wondering if just resealing it would be smart as I will have it out of the car anyhow perhaps a good time to rebuild it?
Also I have read it is smarter to replace it with a later model mustang trans? Does it require much modification and do you think it would be smarter to just junk my old in favor of a mustang variety one?

Thanks in advance for the replies.

P.S.- Motor is bone stock save a cold air intake and its staying that way:)
 
I wouldn't bother resealing it. I'm sure after 100k it's worn out. My opinion buy a 98-02 crown vic (non police) trans, swap some parts to make it work and have a much better trans. For less money at that.
Alan
 
Haven't heard much about the crown vic swaps. Is it much different than the Mustang ones? Also, if I decided to just rebuild mine, is there anything I should look to upgrade in it while it is out?
 
I wouldn't waste the time rebuilding the 94/95 case. In parts alone it will be cheaper to get a crown vic or mustang unit. I wasn't thinking about it being an sc the crown vic unit will only fit mod motors you need a 3.8 or 4.2 core. Sorry about that. I'm so used to dealing with the 4.6 cars.
Alan
 
AOD-4R70W interchange

I have a '94 Mark VIII and accidently bought a fresh rebuilt trans that I was told was for a '95 Mark VIII. After checking the numbers I found that the trans was originally for a '92 3.8 engine Cougar. It is an AOD and not a 4R70W. It bolted right in and the only thing I had to change was the tail shaft housing as the Mark VIII has a larger diameter front yoke than the Cougar. The splines are the same and the overall length of the trans is also. I haven't checked yet, but a trans expert told me that the 4R70W will also mount to the small block Ford V8s as well. It is reccommended that if you install a later trans in your car that the ECM be flashed to the '96 or later specs, only a dealer has the ability to do this, or so I've been told.
 
Thats weird .. the 4.6 engine and 3.8 engine do not have the same bellhousing .. so if the transmission bolted up to your engine, it did not come from a 3.8 vehicle.

Are you sure its an AOD ? How did you hook up the TV cable to the 4.6 Throttle body ? Your car should have a check engine light without the electronically controlled transmission.

You wouldnt reflash the EEC for a later model transmission .. if you use a 96/97 trans in a 94/95, you need to swap the TCC solenoid. If you use a 98+ transmission in a 94-97 car, you need to re-pin the harness as well.

- Dan
 
For the 94/95 4.6 .. you would need to re-pin the Main connector harness, and use the 94/95 TCC solenoid. The shift lever may need to be swapped, im not sure if that is a direct fit. Then you need to figure out what to do about the speedo. If the 02/03 has teeth on the output shaft, it will be an 8 tooth, and you need to use the 20 tooth speedo gear .. I worked on a 94 Tbird with an 00 GT Mustang trans ( 8 tooth shaft ) where the rev limiter kicks in before the 1-2 shift at WOT .. this was fixed by modifying the Valve body to J-mod level 2 specs. Or you could get a chip that would fix this also. If the output shaft doesnt have teeth, you'll need to either swap it out ( rebuild ), or use a seperate speed-cal unit.

- Dan
 
I have a '94 Mark VIII and accidently bought a fresh rebuilt trans that I was told was for a '95 Mark VIII. After checking the numbers I found that the trans was originally for a '92 3.8 engine Cougar. It is an AOD and not a 4R70W. It bolted right in and the only thing I had to change was the tail shaft housing as the Mark VIII has a larger diameter front yoke than the Cougar. The splines are the same and the overall length of the trans is also. I haven't checked yet, but a trans expert told me that the 4R70W will also mount to the small block Ford V8s as well. It is reccommended that if you install a later trans in your car that the ECM be flashed to the '96 or later specs, only a dealer has the ability to do this, or so I've been told.


Someone confused the heck out of your situation. If it bolted in to your markVIII without a new driveshaft yoke it had to be a 4r70w.
Alan
 
Error Correction

My mistake, I said that I used an AOD trans and I should have said it was an AODE. Everything fit just fine until I tried to install the drive shaft. It wouldn't go into the housing all the way, it would start but the seal wouldn't let it go all the way in so, out comes the trans again and I proceed to study the situation and consider my options (which I should have done before making a purchase), I tried the yoke into the tailshaft housing while it was on the bench and figured it was the seal as the spline count and shaft diameters matched. I pulled the tail shaft housing off of the trans and compared it to the one from my 4R70W, all was the same except for the support for the yoke, the 4R70W has a larger outside diameter yoke while the inside is the same. I switched the tailshafts, installed the trans and all is well. No vibrations or leaks and my Mark is doing fine now for several thousand miles. The only down side of all this is my Mark doesnt have the snap off the line that it had with the 4R70W but in all other respects it's working out just fine.
 
Yeah .. with that AODE, you have different gear ratio's in the planetary .. so that is a very small change to your speedo, shift points, etc .. nothing major - but could very well be the "snap off the line". And the AODE has the weaker output shaft, not the best choice for the DOHC engine.

- Dan
 
4R70W v/s AODE and Rebuilders

Yeah .. with that AODE, you have different gear ratio's in the planetary .. so that is a very small change to your speedo, shift points, etc .. nothing major - but could very well be the "snap off the line". And the AODE has the weaker output shaft, not the best choice for the DOHC engine.

- Dan

I agree that it's a weaker trans but it's getting the job done for now. If you only knew of the problems I've had with trans rebuilder shops in V.B. you would understand more fully. 4 rebuilds in 3 years and the last one fully soured me on local rebuilders. The first rebuilt was at a local shop and it lasted about 3 weeks before the new sprag broke. The second one I bought the mechanical diode for it and another new kit and it lasted for about a year before it failed. Took the car to another shop on V.B. Blvd. and the same builder was there, he and the boss promised that it would be done right for sure. I gave them most of a rebuild kit, a 4R70W & a AXODE core with converters. After 10 days and $1015.00 I got my car back and the trans failed in less than 10 miles, I called the shop and was basically told that it was my problem. If I ever am forced into rebuilding again it will be a Ford ReMan or built by Jerry W.. I baby my car and rarely ever do any stop light sprints and never had it at the track. I tried to get in touch Jerry with no luck so when I found this one I bought it. If any one needs to know which shops NOT to take their car to they can send me an email or P.M. and I'll tell them the names of the shops and the builder's name. He talks a good game but on Fords I believe he's in over his head and any successful builds he does is just a matter of pure luck.
 
Trust me .. ive had my share of blown transmissions over the last ten years. 4 trannys on one 1994 LX Tbird alone.

I hope that AODE lasts you for a while, but if not there are a few builders with good reputations that should be able to guarantee or warranty their work.
Bottom line .. if somebody promises anything, get it in writing. :cool:

- Dan
 
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