How hard is it to rebuild an AOD?

In looking for a rwd car for a future challenge project, I found a Grand Marquis that needs trans work. It looks like a performance rebuild kit for an AOD is around $400. I'm reasonably mechanically inclined, but have never done a trans rebuild before. Is it simply a matter of carefully following directions, or is there really some magical skill or special tools needed to rebuild one?

Normally, I wouldn't start with something that needs this much work, but the car is cheap, and at least from the photos, looks pretty nice otherwise. I also seem to recall AOD transmissions are not the toughest thing around in stock form, but can still be built to take some power.

This is relevant to my interests.

Youtube is your friend. I was hell-bent on doing mine until I ran into the need for two or three special seal install tools that were going to cost a couple of hundred.

Rebuild kits are cheap enough.

Ended up hiring it out.

It kind of sucks E36 M3....

You can do it without the install tools, but its a PITA, BTDT.

If you aren't using the commercial direct clutch kit, or included, it's a "worthless" rebuild kit. On mine I just used a plain old regular "paper" clutch rebuild kit on mine and it has a trans brake. There are plenty of decent "factory" upgrades for an AOD, if you know what to buy/look for....

As for what to really look for, it's the 4 cast iron sealing rings on the output shaft. They wear into the aluminum case and will cross leak if worn down. There is a repair kit, but those cases should still be readily available.

Since I have an aod for the challenge car that does NOT need a rebuild, what can we do to make it better and live longer before needing one? It's an 87 out of a 127k town car.

In reply to Dusterbd13:

Should be about nothing.... Those were some of the better built units out there from the factory. Keep it cool and it should last a decent amount of time. Only thing that would be better is it to be an 89-92 unit.....

Any shift kit/manual valve body stuff for cheap? I know you're a tranny guru.

If cheap is about $200 for your budget, yes.

I worked for a guy that used to say to do everything but automatic transmissions. He said they're like women. No one understands how they work and they're easier to take apart than to put back together.

I rebuilt them back when i worked in a trans shop in 05-06 but i dont remember much specific, just general things like if you dont have a clutch hub press or bushing/seal drivers and several varieties of 'actually good and not crappy' snapring pliers you are going to have a terrible time.

Hmm, I think I'm sufficiently scared, so unless this thing is still for sale when a sweet deal on an F250 with a 351/C6 pops up, I'll pass for now.

Ranger50 wrote: It kind of sucks E36 M3.... You can do it without the install tools, but its a PITA, BTDT. If you aren't using the commercial direct clutch kit, or included, it's a "worthless" rebuild kit. On mine I just used a plain old regular "paper" clutch rebuild kit on mine and it has a trans brake. There are plenty of decent "factory" upgrades for an AOD, if you know what to buy/look for.... As for what to really look for, it's the 4 cast iron sealing rings on the output shaft. They wear into the aluminum case and will cross leak if worn down. There is a repair kit, but those cases should still be readily available.

"A" servo

4R70W overdrive hub /clutch drum and planetary set.

Try a filter and fluid change first. You might be surprised.