my 300 SE s a automatic transmission, i found it was leaking fluid at 1 time,where in panic from preventing it from ceasing i put in more than required to top it up.In due time i had the gearbox replaced and the seals changed by a mercedes specialist. once again the car was in tip top shape,until i started finding some drops of transmisssion fluid on the brick work of my driveway. i took it to the specialist on few occasions he said he cud`nt see a thing., eventually whilst coming home the car feels more heavier than it actually was, i find i have to keep my foot on the accelerator to keep the car from slowing down, and if i let go off the pedal the car slows downn really really fassst. can any 1 help here once again ? i took it to hhim and told him the problem, he said its the fuel filter, i had the fuel filter replaced with a so-called other part which it came with but still no -joy! , my own guess is ... i took a look at the rod dipstick inside the enginebay which goes towards the gearbox fluid check. Is it because hes put too much in the gearbox? it looks waay toooo much over the markings .

 

was it a heavy leak?

can you see the source if you lift up the car?

have you tried removing all the fluid and just fill the specified amount... or measure the drained oil?

it's hard to make a guess for me.