So here's the deal. After an engine rebuild we replaced the rear main rope seal. It has been leaking ever since and it has been replaced several times, with several different brands of seal.
The car is an 82 300SD, converted to a manual.
1. The crankshaft has been tested and balanced, it is not bent.
2. We are using the actual Mercedes seal, from Germany. It has a thicker diameter than the after market seals.
3. It is not crankcase pressure related, we have a vented oil catch can.
4. We are rolling not rubbing the seal in, and the ends are trimmed perfectly. *edit* to the 1mm spec
5. We are using "Right Stuff" gasket material, it is not failing there.
6. It fails from the oil pan side. The top stays dry, there is a clear line of oil on the block when the transmission spacer is removed. When you pull off the upper oil pan, you can clearly see where the oil is coming over the seal.

Any help/feedback would be greatly appreciated. Thanks!

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'06 MINI GP - wants to be a race car
'05 F350 - hauls race car
'82 300SD - actual race car
Dirty Little Freaks Racing ~ racing diesel before diesel was cool