[jwmckenzie]

There is a tube that comes out of the rear main to direct oil back to the pan, there is no seal back there. It's a gravity drain back to the pan if any oil gets past the rear main. When you tip the car up, oil can run out of that tube and into the flywheel housing.

Grain trucks would have this problem when they were tilted up to dump the grain into the elevator pit. These engines had a check ball in the tube that would roll back and prevent the oil from going the wrong way in the tube when the truck was tilted up.

Maybe Denis4x4 has one of these in his pickup.