Consequences of Overfilling Transmission

[seafood54]

Quickly asked, ...what are the consequences of having overfilled and driven, albeit unknowingly, a transmission in an 83 300TD?

Thanks....

*explaination... I bought the car, as a rustfree upgrade for my other 300TD and at a price which "helped" me overlook the fact that I found that the previous owner had overfilled the tranny. The tranny has, from the beginning, flared between 2-3 and 3-4, and in exploring the trouble, I have found that the rubber "dust cap" on the Vac Mod was torn, (new one on way) In attempting to adjust Vac Mod to reduce flaring, I have also found that the metal stem of the "T" adjuster in the Vac Mod was rusty. Does this suggest that a new Vac Mod be installed? Does the "dust cap" actually help contain vacuum or is it simply there to keep the adjustment "T" clean?

Thanks again...
Frank................still looking for a good diesel mechanic in the "east of Columbus, Oh" area.