Transmission filter and fluid change

Hi all,I had a few questions I asked a few months ago and was given some excellent advice so thought i would ask again .I have a 95 buick century with the 3.1 engine,I need to change the transmission fluid and filter,my question is when I drop the pan will all the transmission fluid empty from the transmission,does any fluid stay in the torque converter and if so how would I remove it from the converter,I can't afford the have it done at a shop so I will have to do this myself,I don't know what transmission is on the car but I have seen there are 2 different types used ,one has 16 bolts and one has 20 bolts, the one on my car has 20 bolts.Any help and advice would be greatly appreciated,and Thanks for any help......

When you drop the pan you are changine ruffly 1/3 to 1/2 of the total fluid. In order to change all the fluid you would have to disconnect one of the trans cooler lines, have a large container to catch the old fluid, have the engine running, and you will have to pour trans fluid into the fill tube. It can get very messy!!

OK so do I take a line off from the radiator and if so the top or bottom line and do I replace the filter first before I take the line off and do I keep pouring trans fluid in while the old fluid is pumping itself out....I'm not to worried about the mess it will create

And I also would like to know would it hurt or help if I was to use an additive to the transmission like Lucas oil additive and If it doesn't hurt it to add Lucas do I count the additive as part of the fluid refill or does it blend with the trans fluid.....

How many miles do you have?

You have the 4T60E autotransaxle, GM RPO code M13.

And I disagree with what amount of ATF will come out in a pan drop which is better than doing a mediocre flush or a flush without the proper equipment. You'll get about 6-7 qts with a screen filter replacement on a 4T60E. The torque converter will hold about up to 2 qts.

OK so do I take a line off from the radiator and if so the top or bottom line and do I replace the filter first before I take the line off and do I keep pouring trans fluid in while the old fluid is pumping itself out....I'm not to worried about the mess it will create
If you can, remove both lines. Try to get two 3-ft pieces of flexible plastic or rubber tubing to fit over both lines, thep run thos epieces into a drain bucket, to minimize the mess.
You do this after you have changed the filter and reinstalled the pan.

A couple of more tips......... the pan will likely have a lot of residue/debris in ti, so make sure you clean it up.
You should find a small magnet in the bottom of the pan, it looks like a flat donut, about 2 inches in diameter. Be sure to clean it up and reinstall it in the pan. If there is no magnet, its a good idea to buy and install one, as it helps trap and hold ferrous metal particles.
Note, for some reason, almost every mechanic I have ever met seems to throw these magnets out, instead of cleaning them.

As for additives, if your transmission is working properly, don't put in any additives.

Some additives are intended to solve specific problems, like leaky seals etc, and are a waste if your transmission is sound.

I tried the Lucas additive in an '88 Bonneville with a THM440 trans. The additive was designed to reduce friction. Well, perhaps my trans was marginal, but it worked okay until I aded the Lucas during a filter change.

The additive reduced friction enough to cause significant and harmful clutch pack slippage - so much that I had to flush the trnas again just to get that stuff out.

Thanks Guys for your advice and your help my car has 147343 miles on it,I was thinking about doing the plastic tube to a drain pan.So after I change the filter and gasket I run the car til no more fluid comes out of the lines.And this shouldn't hurt it as long as I don't put in gear and shut it down when the fluid stops coming out.I will scratch the additive idea there is nothing wrong with the trans it shifts fine and runs great.This car has been just a dream to own when I got it I had a new radiator put in,I put a new water pump ,intake gasket and alternator and acc.belt a window motor and a fan resistor in it. since I have owned it,other than normal maintenance I have had no real major problems,It has made 4 trips from Louisiana to Michigan and I will be going to Florida at the end of next month,I would also like to thank you guys and gals for all the help and advice you offer to people like me,I think this is the greatest website on the computer and you guys who take the time to offer your advice and tips and answer questions are the greatest people on the computer, again thanks for all the help and advice.....Frank(yankee71282)

You will add fluid to the trans as the old fluid is coming out. All that will happen if you let it run dry is it will push out fluid until the pan is empty, about 4.5 quarts. As you continuously add new fluid it will keep the pan full so that it can continuously be circulated through the trans. I would not let it run dry!!! After about 12 quarts you should be able to see a noticeable difference in the color of the trans fluid. I don't like the additives as well!

With your mileage, DO NOT DO A COMPLETE FLUID FLUSH, only change the fluid that drains from the pan while changing the filter. This topic has been discussed into the ground, and most agree that a fluid flush is a bad idea on a high mileage car. The fresh fluid is grippier than the old, and can cause the old contaminated friction plates to be sheared off their metal backings, ruining the trans and requiring a rebuild. My stand on this topic is simple. If you let the trans fluid get bad enough that it needs to be changed, the damage is done and changing it wont help.

Two points I'd make, buy and use a hand siphon pump, with the right sized hose, I can pump out a lot of the old tranny fluid, and if I'm feeling lazy, I just add new. Dropping the pan and changing the filter is of course better, and easier if most off the fluid is already pumped out.
Other point, the dyi has an advantage and that is time. I let the fluid drip out the the opened transaxle overnight. It will slowly drip for half a day, I figure at least half a pint. I've never messed with the cooling part in front, in my opinion it doesn't hold that much fluid to worry about. --Rural mail carrier, 50 k a year, never had to change a tranny.

When I posted my original response, I didn't notice where you said you intended to run the trans dry. Unless you like changing transmissions, I would not attempt that technique. When you change your engine oil, do you remove the drain plug and start the engine, then let it run until the oil stops coming out? I didn't think so.