I have seen quite alot of detailed discussions where most of the auto trans shifting issues are related to vacuum adjustments or replacing hoses to snug-up the system and/or adjusting the modulator . I have a 1980 240D, (don't have the trans # handy) that shifts fine, (tight, no flaring or slipping, no hard shifts, proper shift points, etc) for the first few miles and even longer when moving. However, if I am stuck in Chicago's stop & go traffic for more than 5 or 10 minutes, there is a pronounced flare between 1st & 2nd and 2nd to 3rd. WOT seems to over-ride this, as it should if the vacuum is adjusted properly. If I stop somewhere and let it cool-down for 20 minutes or so, it's fine again. Coming down from long freeway cruises into traffic causes no issues either, even though the trans and fluid are plenty warmed-up. Almost as if the trans is "air-cooled" and overheats in slow traffic. Is there a trans cooler by the radiator and if so, could there be a blockage there? Any other thoughts?

Another item I forgot to mention was that the trans fluid was recently changed. Until I read some other posts, I was not aware of it's sensitivity to fluid level. Appears that it should be 10 mm under ADD when cold and never over full when hot. I will check this too.
I also flushed the radiator (and entire cooling system) due to PO having the dreaded "green" coolant and re-filled with the correct MB gold. Wondering if the wrong coolent may have contributed to a coolant obstruction that affect the trans circuit? Still need confirmation that there is an internal or external cooler.

OK, so it looks like the fluid level is OK from what I can see in other threads. So is there ant advice on helping to cool the trans?

it's possible that with such an old trans with probably lots of miles that the front trans fluid pump is worn and that when it heats up the fluid pressure drops off somewhat which could cause your flaring shifts since they are made by fluid pressure.you have a trans fluid cooler in the bottom of the radiator and perhaps the best thing for you would be to add an aux air to air cooler to that.pickups used to employ this trick when being used to tow heavy weights which would keep fluid temps down.also poss that replacing the radiator would up the cooling of the fluid.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
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Thanks David, that's a gret idea. The temps reach zero here sometimes though. Would adding a bypass cooler just make winter warmups longer until internal trans friction did the job, or would I run the risk of the trans never reaching correct op temp and shortening its life? I could live with some slightly harder winter shifting for a few miles, but not at the cost of a new trans in a year or two.