Hi supersport6,
Some years ago, after experiencing a 1/2 second hesitation during the 1 > 2 upshift on my then 200+K miles Volvo 740 (when the transmission was cold only), I had Jiffy-Lube flush the transmission. They hooked up their machine in series with the transmission cooling lines at the radiator, then introduced fresh fluid until the color of the outgoing fluid matches that of the new going in...... Gets all the fluid, including the torque converter. Cool!
That ZF transmission always shifted perfectly following that service,
and lasted at least 4 more years without a problem. All that for $80 (at the time). Yes, I'm aware that this flush operation doesn't address the transmission filter issue,
and additionally, I'm not speaking directly about an MB in using that particular example.
Last Summer I attempted to have them do my 560 at the same shop. No Dice! They (the shop) didn't have the correct fitting... Oh well. [xx(]
A week ago I enquired at another local service shop if they could do the car when I bring it out in the Spring, after the salt is off the roads. "Oh, yes we can & What kind of car?" MB 560SEC. That will be $180 to do... Wellll, I think I'll find another shop thank you.
Sorry to digress there, but the point I'm trying to make is that you (my opinion) may have a
high probability of getting good & lasting results from a simple transmission flush at a local service center. Your car has been 'resting' for a bit. Perhaps something internal has stuck due to disuse, varnish buildup, maybe some sediment getting stirred up - I don't know. I
do think a good flush is really worth a shot at this point, rather than living with the symptoms and perhaps causing additional wear on the transmission internals.
Just my 3 cents worth. [

] MBL