Helping a fellow SC owner.. auto trans won't shift out of first??

89SCGUY

Registered User
Guys I need some advice to help a friend. He has a 1990 SC Auto. The car only has 113,000 miles on it. To my understanding our auto trans are generally good for quite a few more miles then this before failure.

The car will not shift out of first gear. If you let off the gas the car still does not shift up. Reverse is functional but that is it besides first. Where to start? What can I check without him having to pay a tow and take it to a shop? I have heard something about the trans being controlled by part of the TB but do not quite understand this.


Thanks in advance guys

Adam
 
2nd part of the question....

I have access to a low mileage trans out of a 91 Tbird 5.0 Automatic I understand that this would bolt right in place correct? I also understand that 5.0 AOD does not use the "A" overdrive servo is this true? However for a "daily driver" vehicle that will honestly be driven slower then hell most of the time would this be a good alternative to an expensive rebuild if necessary?

Thanks again guys
Adam
 
Adam, searching for "AOD" will bring up quite a lot of info. The SC automatics are shifted by what is known as a "TV Cable" which is adjusted up near the throttle body. There's a plastic grommet there which can disintegrate with age and cause it to go out of adjustment. This WILL kill the tranny very quickly, it happened to mine. If it is desired to keep the original tranny for rebuild, try not to drive it. Ford doesn't make that specific tranny with its beefed up parts anymore and the housing on mine was too trashed on the inside to be rebuilt. :( I had to settle for their current replacement which is basically a truck transmission. SC trannies have an SC stamped on them, none of the others do, but from what I've read you can still build one up to SC specs. It's the torque that motor puts out that needs to be built for.
The 5.0 tranny will probably work if it's limited to the use you describe but as I've researched around I've come across refernces to bolt patterns on the bell housing and tailshaft length being areas of variation so that's the first 2 things I'd check. Also 5.0's literally put out almost 100ftlbs LESS torque than an SC< so beware!
 
Adam, searching for "AOD" will bring up quite a lot of info. The SC automatics are shifted by what is known as a "TV Cable" which is adjusted up near the throttle body. There's a plastic grommet there which can disintegrate with age and cause it to go out of adjustment. This WILL kill the tranny very quickly, it happened to mine. If it is desired to keep the original tranny for rebuild, try not to drive it. Ford doesn't make that specific tranny with its beefed up parts anymore and the housing on mine was too trashed on the inside to be rebuilt. :( I had to settle for their current replacement which is basically a truck transmission. SC trannies have an SC stamped on them, none of the others do, but from what I've read you can still build one up to SC specs. It's the torque that motor puts out that needs to be built for.
The 5.0 tranny will probably work if it's limited to the use you describe but as I've researched around I've come across refernces to bolt patterns on the bell housing and tailshaft length being areas of variation so that's the first 2 things I'd check. Also 5.0's literally put out almost 100ftlbs LESS torque than an SC< so beware!


Appreciate the info....I just read through about 13 pages of tech articles on the forum...looks as if the "tv cable" doesn't quite solve the problem if the car won't shift, just if the shifting is late or premature from what I read. Wish it was something simple as that cable, I will check it regardless.

Thanks again
 
I would try changing the fluid and the filter as a cheap remedy to see if anything improves, I had a clogged filter in an AOD in a base 3.8 that caused it similar issues.

Did the AOD shift fine prior to this? I've always had them go where you loose OD then the rest of the gears follow shortly after.

Also the drums can fuse together, had that happen on a 93 I picked up - it wouldn't budge from Park.

-Tim
 
I would try changing the fluid and the filter as a cheap remedy to see if anything improves, I had a clogged filter in an AOD in a base 3.8 that caused it similar issues.

Did the AOD shift fine prior to this? I've always had them go where you loose OD then the rest of the gears follow shortly after.

Also the drums can fuse together, had that happen on a 93 I picked up - it wouldn't budge from Park.

-Tim

Filter/fluid change might not be a bad idea. To my knowledge the trans had no shifting issues until recently.
 
Go with a fluid and filter change, go from there.

Do not go with the 5.0 tranny, its not as strong as the SC tranny. You can get it, it will bolt up, but its goin to go bad after a while. That bepends on how he drives it. If his driving is anything like mine and Tim's, its not goin to last long....LOL
 
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