Transmission Fluid change

[Jae 'Bird]

So I am going to be pulling the car out of storage very soon and the first thing I want to do is change the tranny fluid. I want this to be a thread for others to reference in the future regarding the AOD fluid change and also a double check thread where I make sure I have everything in order to make this go smoothly (and a place to ask questions if something unexpected happens). I will list the tools and parts I have and then you can add things in that I either might want or absolutely need for this process. If I don't mention it, please ask if I have it (parts or tools) even if it seems obvious, I will not take it as an insult, I liked getting double checked. I will also have some questions farther down

So far I've got
- a safe way to lift and support the car
- wrenches and everything I think I'll need to remove the bolts and whatnot
- Breaker bar to turn the engine to get the torque converter bolt accessible
- 12 Qts of Mercon transmission fluid (Canadian Tire still has mercon and it was on sale)
- 1 Qt of Lucas transmission fix
- Wix transmission fluid filter and new pan gasket
- pan cleaning things (brake clean, rags, plastic razor for the sealing surfaces)
- drain pan and a way to measure how much fluid comes out
- Thread locker if I need it but I don't think its needed for any bolts
- torque wrench to properly torque the bolts
- Haynes manual to reference and for the torque specs

The reason for the lucas is I used it several years ago because shifting it was a little sharp and it helped quite a bit, I also like it for a preventative measure going back together to keep the clutches good. I assume this is original fluid coming out as my Dad (the previous and only other owner, doesn't recall the fluid every being changed). However, I have always kept a close eye on it and it is always at the right level and is still a decent pink color so I think I am safe to change it, the car has 181,000 km (112,468 miles)
Now for some quick questions,
I want to confirm that draining the torque converter is fairly easy, I think i just turn the engine until the plug shows and then undo it right? I don't need to remove extra parts to get to it right?
is there any checks or things I should look for while I'm looking at the bottom of the valve body with the pan off?
Are there any torque specs that aren't in the manual that I need to know?
I appreciate any and all input, this will be my first time doing this maintenance.

 

[Zep5.0]

If you have help, you may be able to just crank the engine over with the starter. Just pull the coil wire so it won't start. Otherwise looks pretty good.

 

[3_97_Sports]

Make sure it is mercon v and not just mercon.

 

[97teebs]

Commonly there are 2 different filters count the bolts on your pan to ensure you get the right one

 

[LukesCougar]

Make sure it is mercon v and not just mercon.

Ive made the mistake of using mercon lv. Lasted 2 weeks before it started slipping. Definitely not proud of my past repairs

 

[Kenz]

IIRC since its a 90 it has the older model transmission, Mercon is fine to use. But Mercon V is backwards compatible, and usually considered better fluid.
I did the same fluid change and drained the converter back when I was a teenager on my crown vic. If my dumbass teenage self could do it, can't be too hard. Just take your time and make sure car is supported well. It can be messy though so make sure you have the oil absorber ready!

 

[Jae 'Bird]

Make sure it is mercon v and not just mercon.

I see what you mean, although like Kenz said, its the AOD so I believe I am fine to use Mecon, I could have gotten Mercon v but Mecon was on sale and I figure either way new fluid is gonna be better, I just checked the manual and it does say Mercon, I know either would be fine. Thank you for the check

 

[3_97_Sports]

I realized after I posted that you had said you had an aod

 

[KevinVarnes]

If the fluid has never been changed, when you drop the pan there will be a little plastic plug with an O-Ring in there. It is used to plug the dipstick hole until the transmission is assembled to the car. They just pushed the dipstick into the hole and pushed that plug into the pan. It doesn't hurt anything being in there. Rare to see them anymore since these transmissions are so old nowadays. If you are feeling saucy, you can replace the pan with a new pan with a drain plug on it. Makes future fluid changes much easier/neater.

 

[Generalee0527]

In lieu of the Lucas trans fix, I've had better luck with the Lubeguard additive.

 

[1997ThunderbirdLXV6]

In my experience, turning the engine doesn't require a breaker bar. It's easy to turn with a ratchet.

Make sure you have a large drain pan. The torque converter alone yields 7 quarts.

Removing the pan is much easier if you siphon out the fluid through the dipstick tube first (4 quarts).

The remaining 2 or so quarts are in the various lines, valves, and the cooler. You can flush the cooler by disconnecting the exit tube and replacing it with some translucent plastic tube from the hardware store, going into a receptacle. Start the engine and monitor fluid coming out while a helper pours fresh fluid into the dipstick tube. This process can waste fresh fluid though.