Tried responding to your pm, but not enuff post here yet, Thanks thou for the info.I've never had a zone, but if it did rotate the front diff up a little bit, that would definitely help with the vibration. You're right on the money with the vibration regardless of 2wd or 4wd...on a somewhat regular basis I forget the np246 keeps that front driveshaft spinning all the time (I can't stand that design)
The 241 is a nice transfer case and it sucks your np246 fell victim to pump rub. This spring I'm rebuilding mine when I have the time and putting that aftermarket plate in.
Wish I would've took some pics of it, just had the front diff out to change to a different gear ratio and that was something to do with the stupid 10bolt lol. Learning all the weakness of these trucks and I'm not even ******* it.