How to: Change tranny fluid?

[SmokeyWren]

I need to change the ATF in my Y2K Avalon.

I don't have a clue as to how to go about doing that right, so I'm asking for help.

If it were my Ford diesel pickup, it's easy. Here are the basic procedures for getting it done on the Ford without changing the internal tranny filter:

1a) Be sure the tranny is warm and the new ATF is at least "room temp" of around 70º F.

1) Drain the tranny pan, then replace the drain plug.

2) Disconnect the tranny cooler return line at the tranny.

3) Run a few feet of clear plastic line from the disconnected cooler return line to a bucket or drain pan.

4) Pour in new Mobil 1 synthetic MERCON/DEXRON III ATF - one-third of the total capacity of the tranny - or in the case of the Avalon about 2 quarts. Use a funnel and pour it into the tranny dipstick tube.

5) Crank the engine and let it run until a big air bubble comes down the clear plastic drain line, then kill the engine. (About two quarts should have been pumped out before the big air bubble showed up).

6) Repeat steps 4 and 5. After step 6, there should now be a total of about 6 quarts of old ATF in the drain bucket.

7) Get rid of the plastic line and re-connect the cooler return line to the tranny.

8) Repeat step 4 for the third time. After step 8, you've poured in a total of about 6 quarts of new ATF. A little more than the 5-quart capacity - to be sure we got a good flush.

9) Use the tranny dipstick to help you fill the tranny to exactly full - but not overfull.

Questions:

1) Will that basic procedure work for the Avalon?

2) How do you ID the tranny cooler return line and the tranny cooler hot line?

3) On the Ford pickup, the internal tranny filter is good for over 100,000 miles, so it gets changed about every second or third ATF change. Is that a good policy for the Avalon tranny?

4) About how much ATF will drain from the pan?

Ole Man Smokey
With an ole woman's car and a beat-up ole Ford pickup.
And proud of both of them!

[88 LE]

Originally Posted by SmokeyWren

Questions:

1) Will that basic procedure work for the Avalon?

2) How do you ID the tranny cooler return line and the tranny cooler hot line?

3) On the Ford pickup, the internal tranny filter is good for over 100,000 miles, so it gets changed about every second or third ATF change. Is that a good policy for the Avalon tranny?

4) About how much ATF will drain from the pan?

1. Yes.

2. The hot line (to the tranny cooler) is higher up on the tranny (where it comes out of the tranny). The return line is mounted lower on the tranny (closer to the pan).

It looks something like this:




3. I suggest dropping the pan and cleaning the screen on the filter. Also clean the pan and the magnets stuck to the pan.

4. A few quarts.

[SmokeyWren]

Thanks, 88 LE. Good photo. And good to know this is do-able on my driveway.

What is that third line - the one between the hot and cold ATF lines? The bypass circuit?

BTW, I'm an ole man that has owned over 60 different cars. My favorite so far was an '86 Camry LE with a 4-speed manual tranny that I bought new. Hmmmmm. That was almost 20 years ago. Time flies.

[88 LE]

Originally Posted by SmokeyWren

What is that third line - the one between the hot and cold ATF lines? The bypass circuit?

Theres only 2 lines.

The 3rd line that you see is part of the return back to the tranny. I can see why you think its a 3rd line, but its not.

[SmokeyWren]

Okay, the deed is done. Here’s how I did it:



Gather stuff needed:



--- 8 quarts of ATF rated DEXRON III/MERCON. Almost any brand will do, as long as it’s not a “universal” ATF that’s rated for MERCON V as well as MERCON. I bought Mobil 1 synthetic at Autozone for $5 per quart or $40 total. Dino ATF should cost less than half that much.



--- about a foot long piece of clear flexible plastic tubing – 3/8th inch inside diameter (ID).



--- A 10 mm Allen wrench to remove the tranny drain plug. Or I used 3/8th inch, and it worked too. That’s a big Allen wrench!



--- a funnel to pour ATF into the tranny dipstick tube.



--- Socket set with rachet and mm sockets



--- A pair of pliers to move the hose clamp on the cooler return line.



--- 3 empty one-gallon plastic milk jugs with lids



--- an “oil change drain pan” that will hold about a gallon of used ATF.



1a) Be sure the tranny is warm and the new ATF is at least "room temp" of around 70º F. Drive the front wheels of the car up onto ramps about 8” high or more so you’ll have room to work under the car.

1) Drain the tranny into the oil-change pan by using the big Allen wrench to remove the drain plug. Let it drain until it starts dripping instead of draining. Then put the tranny in neutral and crank the engine. Let the engine idle for about 10 seconds. Kill the engine and put the tranny back in park. More ATF will drain out of the pan. Let the tranny drain until it stops dripping – about 30 minutes. Then replace the drain plug. Pour the ATF from the oil-change pan into an empty gallon plastic milk jug. The jug should have about 3 quarts of dirty old ATF in it.



2a) Optional: Remove the tranny pan and clean or replace the internal tranny filter. Then replace the pan. (This should be done every 2nd or 3rd ATF change).


2) Remove the splash pan under the radiator. This will require removing several small bolts and screws. This is the same splash pan you must remove to change the oil filter. With that splash pan gone, you can see both tranny cooler lines entering/leaving the bottom of the radiator. Disconnect the tranny cooler return line at the radiator. It’s the one near the bottom radiator hose. Move the hose clamp off the barb, then pull the hose off the barb. Mine was very hard to pull the rubber hose off the metal barb on the radiator. When the hose comes off the barb, you will get a few ounces of ATF pouring out, so be ready with a catch pan.



Optional: If you can’t get the tranny cooler hose off the hose barb on the radiator, then you’ll also need a 3/8th inch hose connection barb and two hose clamps that will fit over the hose. Cut the hose about 3 inches from the radiator. Use the hose connection barb to connect the clear plastic line to the short piece of hose coming from the radiator. After you’re done with the ATF change, then in step 7 below use the hose barb connector and the two hose clamps to connect the cooler return line back together.


3) Force the clear plastic tubing over the hose barb coming out of the radiator. Put the other end of the clear plastic tubing in a gallon milk jug.


4) Pour 3 quarts of new ATF into the tranny dipstick tube.



5) Have someone crank the engine and shift it through all the gears, ending in neutral. Let the engine idle until air bubbles come down the clear plastic drain line, then kill the engine. Your one-gallon milk jug should be about half full.


6) Replace the drain jug with an empty jug. Pour in 2 more quarts of new ATF. ) Have someone crank the engine and move the tranny selector to neutral. Idle until air bubbles come down the clear plastic drain line, then kill the engine. Your one-gallon milk jug should be about half full.



After step 6, there should now be about three quarts of old ATF in the first jug, about 2 more quarts in the second jug, and another 2 quarts in the third jug – or a total of about 7quarts of old ATF in the milk jugs.


7) Get rid of the plastic line and re-connect the cooler return line to the radiator.




8) Pour in 2 more quarts of new ATF.



After step 8, you've poured in a total of 7 quarts of new ATF. A little more than the 5-quart capacity - to be sure we got a good flush.

9) Use the 8th quart of new ATF and the tranny dipstick to help you fill the tranny to exactly full - but not overfull. Replace the splash pan under the radiator. Clean up, and you’re done.