We purchased our 01 Winnebago Journey with 3126b Cat in 2018. Purchased it with some oil drips / collection between engine and tranny. I took to Freightliner. They said it was the main seal, if itís not leaving an oil spot on the driveway, just keep an eye on it. Well, 3 years later still the same, but looking a little dirtier/oiler at same place but not really leaving drops on driveway.
I clean radiator / CAC every year but doesnít seem to get sucked up there, no over heating.
2001 Winnebago Journey 36DL
with Cat 3126b & Ď12 Honda CR-V Toad