190e transmission problem!

My son's 93 190e is having a trans. problem and I don't know where to start. He drove the car home the other day and was having no problems; when he went out a couple hours later the engine started but when he shifted to R or D nothing! Park does hold the car but all other gears act as if in neutral? I had the trans filter and fluid changed 4 or 5 months ago, it is at the proper level and doesn't smell burnt. I have made a few local calls and been told several things including "it sounds like a pump gone bad" another guy said that he thought it was an electric switch in the trans. had gone out and if one goes it knocks out all of them. I live 60 miles from the nearest MB dealer and before towing that far away I would like to have a better idea of what it might be. Thanks in advance for any help!

[crookednose]

The car is held in park by a mechanical gear locking. Does the tranny make any kind of whining or bandsaw noise when in gear and the accelerator depressed?

crookednose,

Thanks for the responce but no, no noise, no nothing! The fact that the mech. parking brake works leads me to think that the shift linkage is intact.....or could part of the linkage come off only affecting the forward and reverse gears? I've not been under the car yet. Any other ideas?