My 04 DM LB7 with 90K miles blew about 3 miles worth of blue gray oil burning smoke through the exhaust and has engine oil dripping from the rear mail seal area i.e the connection right behind the oil pan. Here’s what happened.

I had to move the 5th wheel in the yard and decided to go around the block to try out my new Prodigy brake controller. Engine was already warm. About a mile down the road I have a huge amount of oil burning exhaust. Gauges and running noises are normal. I stopped, turned off the engine as there was so much smoke I thought something might be on fire. With the engine off the smoking stopped so it wasn’t coming mainly from oil on the exhaust.

I started up again and had clouds of smoke and headed home. The smoking ended just before I got home. Checked the engine bay-no oil or obvious faults anywhere top side. Oil level was down a part a quart. Unhooked the trailer, drove forward and noticed numerous fairly heavy oil streaks in a wide pattern on the ground.
Underneath the truck the engine oil was dripping from the RMS seal area and had blown all over the transmission etc But the curious thing is that there is engine oil all over the passenger side of the engine.

Checked the oil again and ran the truck into my mechanic. There was no more exhaust smoke. He had just installed a secondary fuel filter the day before and changed the primary filter and said the area was bone dry as was the RMS seal area. Now the RHS of the engine looks like a quart of oil was sprayed on it.

It looks like a blown RMS except for all the oil on the side of the engine and the large amount of oil that went through the engine or the just the exhaust. My mechanic doesn’t think either should happen with RMS failure.
The truck is sitting at the shop waiting for Monday morning. I’d appreciate opinions on whether it is RMS or where to look for another culprit/ thanks for your help.

take pictures and post them. is the smoke white or blue? diesel smoke at least when compression is lost is going to be a whiteish color. what smell was the smoke. either sounds like you have a dead cylinder or a hole in your motor somewhere. the rear main is low, you have a leak somewhere higher on the pass side, its going to make its way lower, and prob make the rear main wet. either way a rear main is the least of your problems, and if it suddenly started leaking and leaking badly its probably a sign of something much worse. any loss of power? did it drive differently? pull your oil cap off with the truck running. was your truck over filled with oil?
you have a mechanic to figure this stuff out right

take pictures and post them. is the smoke white or blue? diesel smoke at least when compression is lost is going to be a whiteish color. what smell was the smoke. either sounds like you have a dead cylinder or a hole in your motor somewhere. the rear main is low, you have a leak somewhere higher on the pass side, its going to make its way lower, and prob make the rear main wet. either way a rear main is the least of your problems, and if it suddenly started leaking and leaking badly its probably a sign of something much worse. any loss of power? did it drive differently? pull your oil cap off with the truck running. was your truck over filled with oil?
you have a mechanic to figure this stuff out right

Exhaust was definitely engine oil burning and pouring outta exhaust pipe...not white or off smellly. No loss of power-good guages, eveything worked normally. Oil level was correct.

thinking turbo related-lines, seals-maybe something loosened, dislodged or pressure when they installed secondary fuel filter.

the turbo get its oil from a passage from the camshaft, if it gets blocked it usually wont make it smoke, it will take out the turbo pretty quick though