Want to do some tranny maintenance, but...

Last year I had a "power flush" done by Tanner Transmissions on my '99 with 150k miles, which they claim changes 100% of the fluid and the tranny filter. I would like to stay on top of the maintenance so I don't have to fork over more than $100 to have this done again in the future.

I would like to pull the drain plug on the tranny pan without dropping the pan and refilling it to the full level with Dex III. I have read that only about 2 liters, if that, will come out of the pan. With this small amount of new fluid, is it even worth doing? I was even thinking that if it were done even as often as a regular oil change, this would have to make a difference in the fluid quality, right? Let me know if I'm crazy and this is a waste of time, or if this might be a good idea. Thanks.

3.8 quarts is what I remember. Factory recommended it every 30,000 miles. Be sure to replace the crush gasket on the drain plug to prevent drips.

jeeperguy21 said:

Last year I had a "power flush" done by Tanner Transmissions on my '99 with 150k miles, which they claim changes 100% of the fluid and the tranny filter. I would like to stay on top of the maintenance so I don't have to fork over more than $100 to have this done again in the future.

I would like to pull the drain plug on the tranny pan without dropping the pan and refilling it to the full level with Dex III. I have read that only about 2 liters, if that, will come out of the pan. With this small amount of new fluid, is it even worth doing? I was even thinking that if it were done even as often as a regular oil change, this would have to make a difference in the fluid quality, right? Let me know if I'm crazy and this is a waste of time, or if this might be a good idea. Thanks.

Click to expand...

You can flush almost all the fluid by cutting into the transmission cooler line and installing a rubber hose that allows draining of the fluid. A flush takes a couple quarts more than the total capacity of the transmission.
Flush until the fluid is the color of the new fluid.

Here are two threads that give the details.
http://www.naxja.org/forum/showthread.php?t=62900&highlight=flush+tranny
http://www.naxja.org/forum/showthread.php?t=993958&highlight=transmission+flush

One of those links above contained the answer I was looking for. I'll paste the post below:

"I heard of people draining the pan, refilling it, driving for a few days, draining the pan, refilling it, driving for a few days....etc....repeating this cycle until they go through a whole case. I guess they don't want to tap into the lines and don't want to pay for a tranny flush, but want to get all the fluid replaced.

The problerm is that you get less and less of the old fluid out of the tranny everytime you repeat the process. I think the FSM says an empty tranny takes 8.45 qts and assumimg each pan drain gets 4 qts out, here goes the math:So going through a case (12 qts = 3 changes) gets out 80% of the fluid, which is probably fine. I was just thinking about this and wondering about the math."

His numbers are probably not 100% correct, but if I can get 80% new fluid in there by doing it this way, that's good enough for me. I'll give it a shot and see what results I can come up with as far as how the tranny fluid looks after a couple of drains/refills. Thanks for your input.

Poor man's flush, FTW.

-Drive normally for 20 minutes ensuring shifting into all gears.
-Drain the pan and then add 4 qts.
-Disconnect trans return line from the radiator to the trans (line entering the trans furthest to the rear) and affix a rubber drain hose to it, and put the other end into a container such as milk jug.
-Start engine and watch fluid flow until milk jug is full.
-Kill engine and add 4 more qts.
-Start engine and watch until fluid runs red then kill engine again.
-fill to hot full hatch marks, and drive.
Finito!

You end up changing out like 90% in one fell swoop, and dont have to use 24 qts to accomplish the change.
GOOD LUCK!

jeeperguy21 said:

So going through a case (12 qts = 3 changes) gets out 80% of the fluid, which is probably fine. I was just thinking about this and wondering about the math.".

Click to expand...

Why get only 80-90% of the old fluid out when, while using the transmission cooler line method, you can get just about all of it out and use much less fluid.
The AW4's dry capacity is 8 quarts and it take an additional quart or two to clear the torque converter for a total of 10 quarts.

Since you had a flush a while ago, draining and replace the approximately 4 quarts of fluid would be okay. It's what they've done for years, at 30,000 mile intervals.

When doing the poor man's flush be sure to do a little at a time. If you drain it all at once it may cause issues such as not getting the air out of the pump and allowing your trans to shift.

all the tranny fluid is stored inside the torque converter . if ur torque converter has a drain plug (most do ) spin the motor around and find the plug
(usually a hole in the flex plate with a square head plug) . u can never get 100% of the fluid out of the transmission while its in the car . but 50-75% of fluid is stored in the torque converter thats what makes the converter work .draining the pan is only bout 20% of the fluid ...

first open a new bottle of tranny fluid .. smell it .. now pull ur dipstick . smell it does it smell like rotten eggs .. then its time to change the fluid

Mesh said:

There's a reason why the pan is angled so you can't drain all the fluid. In Higher mileage transmissions the friction plates are starting to get warn and the old friction material keeps them going.

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this is true also but burnt tranny fluid loses it lubricating and fluid coupling capabilities..the clutches are not what makes the car move and shift properly
this fluid also serves as a coolant and a viscous fluid that transmits power from the engine to the transmission.

a lil info on fluid coupling-

The pump inside a torque converter is a type of centrifugal pump. As it spins, fluid is flung to the outside, much as the spin cycle of a washing machine flings water and clothes to the outside of the wash tub. As fluid is flung to the outside, a vacuum is created that draws more fluid in at the center.
The fluid then enters the blades of the turbine, which is connected to the transmission. The turbine causes the transmission to spin, which basically moves your car. the blades of the turbine are curved. This means that the fluid, which enters the turbine from the outside, has to change direction before it exits the center of the turbine. It is this directional change that causes the turbine to spin.
In order to change the direction of a moving object, you must apply a force to that object -- it doesn't matter if the object is a car or a drop of fluid. And whatever applies the force that causes the object to turn must also feel that force, but in the opposite direction. So as the turbine causes the fluid to change direction, the fluid causes the turbine to spin.

u dont change the fluid to only lube the clutchs and gears u change it to replenish the fluid coupling abilities of the fluid.. .
this is why if installing a HIGH STALL converter it must be filled before installed or u will ruin the torque converter instantly to no repair

also alot of newer cars -2000-2010 have Lifetime transmission fluid and are not recommened to be changed such as audi-mercedes-bmw-new fords. as some jeep trannys are made by mercedes.

I change the tranny pan fluid (as mentioned 3-4 quarts) about every 15-20K. Easy to do as changing your oil.