Minor rear main seal issue with OBD2 swap!

[DesertBMW]

I am experiencing very minor leak problem at the rear crankshaft seal with M52/S52 OBD2 crankcase ventilation system swaps. Leak is very minor, like one drop a day but it gets old after while and I did the job correctly on both cars so it should be totally dry there.
Seals are new old style spring loaded lip. Are you guys experiencing the same leak?

My theory is that with E34 oil pan oil slushes backwards during acceleration splashing the rear seal, and crankcase ventilation is at negative pressure(obd2), this weakens the spring load on the seal lip and makes some of the oil past the seal.

With OBD1 setup there is no such problem because crankcase is always at neutral or positive pressure.

[328ijunkie]

We use springless RMS's in all our swaps and havent noted any issues... The spring types usually cut into the crank and once a groove is made then there is no saving it. Are your RTVing the base of the RMS cover plate?

[agent]

I bought the RMS kit (not just the replacement seal) on RobertK's advice. My OBD2 swap doesn't leak a drop.

[DesertBMW]

We use springless RMS's in all our swaps and havent noted any issues... The spring types usually cut into the crank and once a groove is made then there is no saving it. Are your RTVing the base of the RMS cover plate?

I avoided using springless seal because they are $100 that come with housing. Unless you can tell me were to buy just the $25 seal. I did use ultra gray silicone and made sure everything looks fine. Did the OBD1 car before this and no problem.

[328ijunkie]

Matters how fubar the crank is. We get 'payen' springless types for ~25-30$ from worldpac

[DesertBMW]

My shop has worldpac account, I looked up the seals and all they got is old traditional seal.

[328ijunkie]

11142249533?