I've recently posted an issue about blowby of my rig. Now that i have stopped the vacuum pump oil leak, i know where, and when the oil is leaving. With just the rig "no trailer", there is just a little blowby at normal speeds. If i hook onto a sizeable load, When i get where i'm goin, the whole front of the trailer is covered with spots of oil, and the undercarrige looks like a river of oil. Especially the front drive shaft under the blowby tube. Any advise on causes or reasons would be appreciated. Oh by the way it uses about a half a gallon on a 60 mile haul.

 

https://www.dieseltruckresource.com/...s-t255498.html

A little reading to get you started. There are other threads too if you search.

 

Hopefully your engine doesn't need a rebuild.
Someone on another message board reported exactly the same problem when he switched to synthetic oil.
Problem disappeared when he switched back to dino.

Other folks have said that installing one or even two crankcase vents on the valve covers like are used on Ag equipment 5.9s solved the problem.