Changing Transmission Fluid - AOD

R

racer02sl

Registered User
New SC owner. I have a 93 Super Coupe with the AOD transmission. I would like some help with changing the transmission fluid. Here are my questions;

1. Does anyone have a step-by-step procedure?

2. If no step-by-step procedure, how are you guys draining the fluid from the torque converter? I thought there might be an access hole with a rubber grommet to get to a drain plug similar to my Mustang, but didn’t see one.

3. What type of fluid should I use? I’ve read over many threads about this, but It hasn’t been clear on what type, or if Mercon V is safe to use.
 
93's don't require MerconV and it might even cause problems with old seals etc... I'd stick with the dextron II ,and there is a plug on the separator plate inside the indention in the rear of the oil pan, Pull the plug and turn the engine to access the torque converter drain............Dan
 
I think the step by step procedures are here somewhere...i'd do a quick search. It's not hard at all....just messy.

To get to the torque converter plug just turn the flex plate via access cover until you see the plug...11mm socket is used if I recall.

It would be a great time to do a trans cooler and If you plan on keeping the car I strongly suggest a deep fluid pan WITH drain plug...once you do the fluid change you will know why a drainplug is an awesome thing to have. It will save you the mercon/dexron bath :p .

GOod luck man!
 
heres what they won't tell you

if you have a high mileage automatic trans that hasn't been maintained, thus it has brown or burnt trans fluid, changing the trans fluid is more than likely going to kill the trans

if it has over 100k miles and the fluid is not beautiful pretty red, just forget about it and keep going

I've probably changed 15-20 trans in my life that fell victim to trans flushes, all of which performed flawlessly prior, 2-4 weeks seems to be about the ideal lifespan
 
also about the mercon bath... yeah that gets old real fast like

if you have a vacuum pump, you can put a tube in the dipstick tube and suck a majority of it out, makes life much more enjoyable

also, when removing the pan i usually take all but 4 bolts out at each corner, then i break them loose and work my way down letting it lean to one corner, armed with a catch pan and quick hand movements, it keeps the job relatively clean
 
decipha said:
if you have a high mileage automatic trans that hasn't been maintained, thus it has brown or burnt trans fluid, changing the trans fluid is more than likely going to kill the trans

if it has over 100k miles and the fluid is not beautiful pretty red, just forget about it and keep going
Click to expand...

I lost a tranny that way too...
Unless you can prove it was maintained well don't touch it!
 
my trans fell into that catogory. the PO drove the car and thats it no real maitnance so when I got the car id maybe 2qts of tranny fluid and allt the pan bolts were loose causing a leak and to make thing worse she was adding type F fluid so I did a flush and installed a cooler and now the tranny will either shift hard if I adjust the TV cable tighter or if loose I have no forced down shifts till WOT and at heavy accel like my 92 had. so my tranny needs a good rebuild all due to the new fluid.
 
Well...shouldn't be posted, but try ripping the tranny in two. It was a late model tranny and I did a nice little launch from a stop sign just to smell burnt tranny fluid a few minutes later.

Well, it seems the tranny, while in gear wanted to separate causing all of my fresh tranny fluid to become undercoating on the bottom of the car.

-Corey
 
decipha said:
heres what they won't tell you

if you have a high mileage automatic trans that hasn't been maintained, thus it has brown or burnt trans fluid, changing the trans fluid is more than likely going to kill the trans

if it has over 100k miles and the fluid is not beautiful pretty red, just forget about it and keep going
Click to expand...


I did a transmission fluid flush on my 96 Mustang with the 4R70W 2 months ago. I had a torque converter shudder for the past 8 years and one day I decided to change the old fluid with Mercon V. It turned out to be the first transmission fluid change ever because I found the white dust plug laying at the bottom of the pan. The car had 220,000 miles on it then! Now has 225,000 and shifts perfect with no shudder.

Since this was a success, I was thinking I might as well flush the transmission fluid out of my Super Coupe AOD, BUT, after reading a couple posts, Is the AOD more vulnerable? When I drove the Super Coupe home, It seemed to shift fine. I thought it shifted into 3rd kind of harder than what I’m use to, but maybe this is normal? I didn’t feel any shudder while driving, but at every traffic light or stop sign, I did feel some vibration that went away once I took my foot off the brake and started accelerating…

So if it’s not a good idea to flush the old fluid out of my AOD and add new, is it safe to add new tranny fluid if I’m a little low on the dipstick???
 
You could try a simple pan drop and filter change which only replaces 5 of the 12 qts in the transmission if its acting up, or just fill with new Merc III grade as needed.

The 4R70W's were known for shudder due to fluid put in them, but the AOD's are not known for shudder. They are known for frying the OD band, which then basically leads to a full rebuild.

Sounds like you may just need a tune up of plugs and wires to help with your rough idle condition.
 
rzimmerl said:
Sounds like you may just need a tune up of plugs and wires to help with your rough idle condition.
Click to expand...

I would say the vibration at traffic lights and stop signs isn't a rough idle condition. It idles fairly smooth in park and neutral. When stoped in drive, the idle was around 650-700 RPM and some shaking was occuring and goes away once I let off the brake.
 
Last edited:
rzimmerl said:
You could try a simple pan drop and filter change which only replaces 5 of the 12 qts in the transmission if its acting up, or just fill with new Merc III grade as needed.
Click to expand...


It seems like I've heard from somewhere/someone that you shouldn't mix new transmission fluid with old, Or maybe it was to never mix two different types of tranny fluids...or you shouldn't do either one?
 
Last edited:
I want to flush out my fluid and on other cars I've usually used a hose on the coolers line into a container while dumping fluid into the fill tube, engine running.

Does anyone know off hand which line leading to the transmission cooler in the radiator is the "IN" line ?? drivers or passenger side.
 
terralex said:
I want to flush out my fluid and on other cars I've usually used a hose on the coolers line into a container while dumping fluid into the fill tube, engine running.

Does anyone know off hand which line leading to the transmission cooler in the radiator is the "IN" line ?? drivers or passenger side.
Click to expand...
You would have to ask that... its probably quicker to do a search for the answer. I've tried that running the engine thing with a line open, but it didn't work very well for me. Not sure why.

As for me, I just park the car so that there's a tilt forward and siphon out as much as I can. Then drain the converter. That usualy gets a bit over 2 gallons worth out, without the mess :), leaving around 3 quarts in the case itself. To drain that, I remove the pan, take off the filter, loosen the VB a lot and let it drain for an hour or 2.
 
I've searched and found a lot about sucking out the fill tube, how to drain a converter, when to and not to let fast lube places use a "T-tech" on your car and a whole world of stuff including one guy who is talking about using Mobil 1 motor oil in there :eek: (What the .... is he thinking) but no one has mentioned which cooler line is which.

I do this on my turbo Volvo about every 25K and it works great. You just want to make sure you take the right one off or you have a hell of a mess.

May end up with that down hill parking, sucking. I'm just looking to get some better fluid in there for now and next year try some upgrades on it. I'm getting a little shudder and the fluid is 18 years old !!!
 
From silverfox: aod hot out is top, cool in bottom

So you'd need to trace it from the trans itself to the radiator to figure out which is which.
 
Drop the pan, install new filter and pan gasket, refill with proper fluid. Drive it for a week, drop pan again, change the fluid again, filter SHOULD be fine. Drain the converter if possible as well.. NEVER have a trans power flushed, biggest mistake ever. It can break free fine particles lodged in places and wipe out your trans. Unless there is alot of very fine, black particles in the pan, or metal of any kind, I'd bet it would be just fine. If the fluid is brown then it needs to go, means its probably burnt and is doing damage. Whole job shouldn't take more that 2 hours or so. Definately do what was posted earlier about removing all but a few corner bolts, saves a HUGE mess.. On ya, and NEVER EVER use RTV silicone sealer on any gaskets, it's a killer to any A/T...
 
You must log in or register to reply here.
Back
Top