93 ATX Replacement

[Larry Bialecki]

OK, its time to start on the fix for my ATX problem. I would like to get comments on
my plan from the forum and get some additional information. The "Search" function is
OK but I am looking for final verification.

My 93 SHO now has 170K on it with no ATX repair to date. Over the last 4 months I
have identified a 3 to 2 power downshift problem that occurs when in 3rd at 30 mph
and I demand acceleration, particularly when hot. With this situation I will get the 647
error (3rd gear problem) and the computer will change the transmission shifting
schedule to bypass 3rd . Turning the car on and off resets the computer and every
thing returns to normal. There is no slipping as far as I can tell, no gunk in the pan,
and the shift solenoids are electrically being activated properly. I suspect my
valve body/solenoids are acting up. I now manually down shift to 2nd, with foot off
the gas any time I suspect I will be requiring a power down shift to 2nd. Very benign
driving. I have flushed out the ATX.

My plan, over the next couple of months, is to locate a replacement ATX from the
junk yard and purchase it. Pull off the valve body, inspect it/rework and replace the
one in my SHO with the new one. This does not require ATX removal, just care.
Then road test the car and if good, than OK.

If road test is bad, I will then have a good ATX outfit rebuild the ATX I got from the
junk yard. Put on the reworked valve body, and replace my old ATX with the rebuilt
one.

Here are my questions:

1. I hear that the 93 ATX is a poor design and that replacement with a 94 ATX
is better. On what type of Ford vehicles would I find an ATX that is a form fit function
replacement for the ATX on my SHO? Do I have to change out the computer?
If so can I just change the software ROM? I am happy with the present shifting
schedule with the exception of the problem.
2. When locating an ATX in the junk yard what should I look out for?
What should one expect to pay?
3. Can I trust AAMCO to do a good rebuild job on a transmission I bring in?
Is there a better place to go. I am located near Los Angeles. About how much for a
rebuild?
4. After reinstalling the ATX do I need to do any adjustments?

Any comments will be appreciated and I will keep the forum informed on my progress.

 

[RTStabler51]

I'd only get one out of the SHO. But IIRC Continetal would work. AAMCO? if you want to have to continously go back to them. My suggestion is go to SHO Shop and get one. (IIRC They sell FPS ATXs). It will be more than AAMCO, but well worth it.

also IIRC the 94/95 have 25spline input shafts? v the 93s 23??? Also the EECs aredifferent between the 93-94s, i'd invest in that too.

<small>[ December 09, 2002, 11:44 AM: Message edited by: RTStabler51 ]</small>

 

[93nighthawk]

The guy you need to talk to is Doug Lewis at FPS. He is THE MAN when it comes to ATX rebuilds, It will last for ever, and there are a couple members running 300+hp through it with no problems. You are looking at $2500-$3000 (depending if you pull the tranny or send it.) for a rebuild. About the same price at amcco or any other trans shop. I would go with the best.

Eric