I called Redline and Valvoline re their ATF recommendations
 

For my 190E 2.6 with 173k, Redline recommended their D4 ATF in place of Dextron lll. Redline stated it would increase the life of my transmission (my main concern) and NOT cause it to start leaking. Valvoline recommended that I use conventional Dextron lll and to avoid synthetic due to possibility of leaking due to increased cleansing. He also stated that NAPA ATF is identical to Valvoline. So...what to do?

You can use either. Both are fine. I always use the cheapest Dex. III I can find and never have had a automatic trans. related issue on multiple vehicles with hundreds of thousands of miles.

Just be sure you get as much as you can out and change the filter. I would not recommend a machine flush. Just drain and fill.

followup on atf
 

I decided to go ahead and change the atf in my 190E 2.6 with the pricey Redline D4. There is a noticable improvement by quicker and more positive shifts. It had Valvoline dextron lll in it with only 15K on it. I didn't think there was a problem at all. There was some sludge in the bottom of the pan at that low milelage. I changed the TC and filter also. I'm glad I went with the synthetic redline.

If the sludge in the pan was gray, it probably was friction material.

the sludge
 

The sludge was grayish. Also,the fluid was brown with only a slight reddish tint left. If the sludge is friction material, what doe that mean? Do I need to worry? anybody know? thanks

When my trans blew 4th gear/reverse a month and a half ago, the pan had globs of grey material in it, and the fluid had a hearty quantity in it as well....it drained with gray streaks in the fluid! :eek:

I use the Valvoline Dexron VI Full Synthetic in all of ours, no leaks, no issues, and they shift great, especially in the super cold, that is where I noticed the most difference in shift quality.

Does the transmission slip? If so, it is likely on its way out.

Now you need to find out if the slipping is because the friction material is mostly gone, or because the hydraulic pressure in the transmission is too low and not completely engaging the clutches/bands (in which case it might be adjusted and salvagable).

does it slip?
 

no slip at all. it feels great. quick and robust shifts. my wife who got the car when nearlly new said it's just like it was when new. So, what do you think? good for a while? or impending doom aeround the corner?

Drive it, if it has no driveability problems it's probably fine. It's possible that the pan hasn't been dropped in a long time and the fluid changes have been done (if at all) by the notorious "flush" method.