Solenoid my azz, typical car sales statement. I always laugh when I hear "it's just a sensor" or "don't worry, it just needs a recharge". Because, if it was really some $50.00 fix, do you honestly think they wouldn't already have done it instead of taking a lower price on the car? Deanyel got it right, it's time for a rebuild.

The 722.3 hydraulic trannies are weird like that. If the car is driven all the time, they will last easily 200k+ miles before needing a rebuild. But if it's a car that just sits a lot, they tend to die a very early death. I have seen many other MB's with the hydraulic 4-speeds that were shot at way less than 100k, and almost every one was in a car with excessively low mileage. I don't know if the fluid needs to circulate to moisturize the bands, or what the cause is.