1990 AOD... no overdrive, help!

So I picked up my cougar today, and with my luck, as soon as I pull on the freeway, it goes into o/d and it was like shifting into neutral, no engagement, no funny noises, just like if it was popped into neutral. Drive position works just fine, and runs smooth. So what couldthis be? Car was working when parked, sat for about 2 years or so, and now the o/d doesn't work. Im gonna drain the fluids, and replace the filter tomorrow, but what else should I be lookin for? Should I take it to the ford dealer and have them fix it? Could it be just like a junked up valve body, and some cleaner fix it right up? Or am I screwed, and need a new tranny?
[addsig]

I have the exact same problem i have a 91 thunderbird sc does same thing if you find out can you let me know.

Again, I learned this lesson with the wife's 1990 T-bird.

The O/D band is smoked. We drove it in D for a year before I went in and replaced the band. I also installed a "B" O/D servo out of a 5.0 AOD.

This caused the O/D shift to be extremely firm. Wife hated it, but it never slipped again.

BTW, the band initially fried at less than 60k miles. Fixed it at about 80k, and it was still shifting hard at 150k when we sold it.

Total cost was less than 100 bucks.

Good luck!

Greg

How hard is it to replace the band? Would it be something that an average car guy like me could tackle in a day or two? I got all the other problems sorted out, idle was a really dirty idle air thingy, a good blast of carb cleaner cleaned it right up. Overheating was the water pump that was dead, 70 bucks later, and a few hours, the car is now registered in my name, with current tags. Passed smog with near zero (only 0.03 % CO at idle, zeros everywhere else) and its way comfy to drive. The digital dash says im getting 25 mpg, even with no overdrive. AOD shifting sucks, it goes into the highest gear as soon as possible, shifting around 2k or so sometimes ugh...
[addsig]

Brian, I did my own band in the T-bird, but it was a pain in the butt.

Gotta pull the gas tank, driveshaft, exhaust, tranny x-member and tranny.

Then the work starts.

I bought a soft parts rebuild kit, which is just seals and gaskets. I purchased a new AOD band, but people say the AOD-E band is better now. The O/D drum was scored and ruined by the bad band, so I picked up one of those for 10 bucks used at a tranny shop. Also got that "b" servo for free from the same place. Had them press in a new tailshaft bushing while I was there.

To replace all this stuff, you remove the pan and valvebody from the trans. Then pull the front pump out. This will let you slide all of the driven guts out of the tranny. The O/D drum can then be removed. There is a set of clutches inside this drum, so gotta yank a circlip out and place all these into the replacement drum(if you've had to get a new one). Slide all these rotating parts into the trans case, and check for endplay. I believe I had .060", which if I remember right was right in the middle of the spec.

As for the valve body, I did not intend to mess with it because it was working properly, but I broke a gasket and had to disassemble, clean, and scrape out the broken gasket. Be extra careful here, you do not want any particulates in the valve body. Also, you want all springs and balls to go back in their correct places.

Put it all back together and enjoy cruising at 1800 RPM!

I played with the TV cable (the shift cable on the throttle body) until I had the shifts moved up a little bit. The trans will live longer with higher shift points. If the trans is shifting early, it will soon die.

Good luck, and remember I did this job 4 or 5 years ago, so I may have left some things out.

It can be done with a good set of 24" jackstands and a transmission jack is MANDATORY. That sucka be heavy, now!

Greg

Greg P

Do you loosen ot tighten the TV cable to move the shift points up to a higher RPM?

Thanks
[addsig]

Coupe, you tighten the cable to raise the shift points. This is an extremely fine adjustment, like 1/4" or less from the factory spec.

Also, this only adjusts part throttle shift points.

Hope this helps,

Greg