Hello: I have a 1990 300SE. I want to change the trans fluid and filter. I can't find a specific DIY post for this job even though I've searched and searched. I do recall seeing one some time ago, but I never saved it. I saw a detailed one, but it was not for the same trans. If someone can send me a link to the one I need I'd certainly appreciate it.
I've read that there is a bolt on the torque converter that I need to remove in order to drain the converter. So that I can have everything ready for the job, I'd like to know if there is a seal on that bolt that I will need to replace. Also, what's the correct procedure for turning the engine in order to line up the torque converter bolt in order to remove it?
I appreciate your replies. Thank you in advance.

Frank, it's pretty straightforward.
I don't have the exact wrench sizes in front of me, but I'll give you what info I can from doing it several times.

Pull the pan drain plug with an allen wrench (5 or 6mm I think) and let it drain out (2-3 qts maybe).
The plug torques back in at about 7 lb/ft, or a good snug turn of the allen, the metal washer can be reused with no problem.

Pull the pan (13mm socket I think) and drain the rest, clean up the pan and inspect the gasket. The pan has flanges that keep the gasket from crushing, so it can often be reused if still in good shape. It torques at about 6 lb/ft. or just a good snug turn. You wil feel the pan flanges snug up and resist further tightening.

Unscrew the filter (very straightforward) and replace with the new one. Be sure the old seal ring comes out with the old filter.

Turn the engine over clockwise (from the front) using a big socket on the front crank bolt (1 1/16 I think). Don't turn the engine backwards, not so good for the chain tensioner.
The converter plug is located behind a little sight port on the bottom of the bell housing. it's kinda hard to see, it's actually up the side of the converter shell about 1/2 inch. It looks like the pan drain plug. It's washer can be reused also. You will get a lot of oil from there, maybe 5 quarts.

Snug everything back together, add about 4 quarts (too much at once can actually run out the tube and make a real mess). Crank the engine for a few seconds to circulate the fluid. Then add the rest. Don't overfill. Get the fluid to show up on the stick, then set it a bit below the MIN line and go for a short drive. The fluid should be set right at the middle mark when the trasnny is at normal operating temp, say, after a 5-mile drive.

Piece of cake,
DG

Thank you for your help. I have a few other questions. As I stated in my original inquiry, this is for a 1990 300SE. I'd like to know if I have to remove any cross member as I recall seeing that in another post somewhere. Perhaps it was for a different car. I will be using a new seal and filter, so following your procedure, after I replace the filter I should replace the pan and move on to the torque converter, correct? That is, there's no reason for me to leave the pan off and the new filter exposed at that time, right? Also, I will be doing this on my back in my driveway. Is it OK for me to have the front of the car up on ramps? I'm not worried about getting the last ml of fluid out, but I'd like to get out as much out as is possible given my working atmosphere.

No crossmembers to remove. Yes, you can do the pan and the converter separately. No problem with it sitting up in the front, when you drop the pan virtually the same amount will drain out regardless.
I guess most logical way would be to do the converter, then pull the pan drain, then the pan. As I remember, you get only 3-4 qts from a pan drain, and another 4 or more from the converter. I only do this about every two years, and I tend to forget a lot of details these days. But there are no big surprises, very straightforward once you find that darn convereter drain plug.

DG

I thank you once again for you help sir. I'll give it a try in the next few days.