The is a WIS procedure for ATF in the coolant. Essentially, the recommendations are to replace the radiator, flush the system with special MB 'degreaser' (PM me if you want the part no.) and maybe add a dedicated transmission fluid cooler.

I just recalled that MB made a change (~W211). In the W210 the coolant is scheduled for flush every 3 years. In newer models the coolant is scheduled for flush every 15 years! The newer radiators have a built in chemical pack to help prevent corrosion.

Im on the fence on installing a trans cooler, I know its good for towing but wont it hurt the trans if it runs too cold all the time like a car that wont tow anything and a trans that locks the torque converter.

The 722.6xx was used on the V-8's and the V-12 so it's should be pretty robust. People in Europe tow with these sports wagons since pickup trucks are not to common.

Yep back in the day they were rated by max torque of the engine, I remember the abbreviation for them is "NAG", I think one was 580, I can't remember the other but could look it up, but there were only 2, one was for 4 cyl and 6 cyl, the other was for 8's and 12's.

330 and 580:
Mercedes-Benz 5G-Tronic transmission - Wikipedia, the free encyclopedia