Here are the facts:

Every time I run the car for any amount of time, when parked, it deposits a 3-inch spot of oil. Oil drips from the transmisison support, midway between the transmisison mount and the bracket which secures the exhaust. The oil is clean and seems to come from directly above the rubber transmission mount.I periodically have to refill my trans/overdrive with 30w Non Detergent.There does not seem to be an abnormal amount of oil coming from the bell housing weep hole, in fact, barely any. (I've had Volvos for 30 years and know about rear engine seals.)

If I had to venture a guess, I'd say it's comning from between the trans and overdrive. Does anyone have experience, recomendations? Could it be as simple as tightening the bolts which secure the OD to the trans? Could it be a seal or gasket failure?

I have a rear U-Joint that's going so I plan to take the driveshaft out, replace that, and examines the center support bearing on the shaft. I understand that the OD can simply be unbolted and removed without taking out the transmisison (I have an M410 so the bell housing has to come off with the trans.) But my goal is to repair that leak with the minimum amount of screwing with the overdrive.

I'll await your sage advice.