Is the engine oil drain plug on this model M18x1.5x12 or M14 1.5x12? Trans and final drive should be M 14x1.5x12, correct? Just a bit confused as I ordered new drain plugs and all three that were sent are M14x1.5x12. I am also going to use Rotella 15W40 oil in the crankcase. Any of you learned hedz have an issue with that and why? Also any brand recommendations for 80/90 hypoid gear oil in the trans and final drive. Sorry, not trying to start another oil thread, just seeking suggestions!