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How to change aod tranny fluid?

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12K views 13 replies 5 participants last post by  bronzesink8  
#1 ·
This might be a stupid question but i've never done it before. How do you change the tranny fluid on an aod? Why do most people take it to a shop instead of doing it themselves is it that hard? How much and what kind of fluid will I need? I have a tranny cooler and shift kit but the rest of the tranny is pretty much stock... thanks!
 
#2 ·
Just jack the car up securely.... Loosten the bolts... The key is to let one side of the pan down to drain some , then undo the other bolts and let it totally down.... Then there will be the filter youll have to unbolt.... After that just clean the pan out , put on new gasket/filter and bolt up securely... I used the recommended trans fluid for the trans... Dextron3 or whatever it is...... :)
 
#3 · (Edited)
I do what red89notch does AFTER I warm the engine to operating temp. Then I disconnect the top transmission line at the radiator and screw in a fitting connected to a drain hose, (OR SLIDE THE HOSE ONTO THE TRANSMISSION LINE DEPENDING ON WHETHER YOUR TOP LINE IS PRESSURE OR SUCTION), into a five gallon bucket, (I added one quart marks with a magic marker on the side of the bucket up to 12 quart mark). Plug the open line to the transmission, (OR THE RADIATOR), to keep the dirt out.

Open the oil and set it where it won't get knocked over.

The next part works best if you have a helper in the vehicle.

Start the engine and as the ATF flows into the bucket - add a quart, at the filler tube, as a quart flows out. If it flows out faster than you can pour it in, (some of the older cars would pump slow enough that you could keep up), have your helper stop the engine if you get more than two quarts behind. When you catch up - have him/her start the engine and continue the exchange. When you have run the required amount out - shut the engine off when it is about a quart short. Connect the transmission line back up to the radiator and top off the transmission to the full mark.

Have done this on a number of vehicles with no problem. The only hitch is: on some vehicles the top tranny line is pressure and some are suction?

Believe it or not!
 
#5 · (Edited)
For me I would jack the car up and put jackstands on the 4 corners... the I put a syphon tube down the filler tube (the kind of syphon pump with the shake ball) and drained it into a bucket that way..

I did this process for a while... Then I got smart and bought one of these.. they are only $36.88 from Summit Racing... thicker gauge metal, chrome and the best feature A drain plug!!!

Image
 
#7 ·
nottoofast50: What red89notch said is exactly the way you do it.

MYLITTLEHO has a good idea because it is such a mess trying to remove the pan while it is hot and full of oil, (kind of a balancing act if you don't leave some of the bolts on one side like nottoofast said).

I just like to exchange ALL the fluid. Changing 3 of 9 or 3 of 12 qts is like draining 1 or 2 qts of engine oil out, changing the filter and leaving 2/3 or 3/4 of the dirty oil in? Do you/would you do that?
 
#8 ·
Yep, drain the converter too that's another 4-5 quarts of old dirty fluid in there too....

Once I drain the trans I let it drain for several hours to get every drop I can and it also means less drips and such when you actually pull the pan...
 
#10 ·
Just to add to Mylittle50's post. I bought a drain plug kit from the local speed shop and put it in my stock pan. Messy the old way and way easier now. Just drill the right sized hole in the pan and never get soaked in trans fluid again.
 
G
#11 ·
Maybe I'm not understanding the posts, but couldn't you just drain all the fluid out of the tranny at the radiator with the engine on in park, then take off the pan, clean it up, replace filter. Reverse steps and add fluid. Seems like I remember talking to Len Bertrand at Lentech about this and he said that it wouldn't bother the tranny if it was in park as long as you turned the motor off as soon as the last frop of fluid came out. But maybe I'm not remembering the conversation. I do agree, though, that getting all the fluid out is an excellent idea.

Other notes:

The pan is around $100 from Summit.
Use a torque wrench on the pan bolts and on the filter bolts. An inch pound wrench is handiest.
When you put the pan back on, push all the bolts through the gasket. I go with the neoprene gasket sets and the first time I bought one (from NAPA) I made sure that the bolt would go through the gasket and the gasket would hold it. Otherwise, you have no idea if you are going through the gasket or are missing the gasket completely when you're underneath trying to put the pan back on.
 
#14 ·
ARM92GT: Suppose you could but, with some of the pumps and bearings inside I prefer to add new as the old is pumped out AFTER replacing the filter and cleaning the pan.

Can't knock it if it works.