I know this post is old as all get out and you probably have already fixed it.
I had this same problem with my 05 WK 5.7 limited.
Dealership first said clutch packs, trans case fluid and differential fluid.
Quoted me 450.
Then it got worse. Had them look at it a second time. Broken differential mount. Labor and parts 550. (ouch)
And they showed me how my CV joint was screwed up on my front driveshaft. I mean blew it out. Quote 760.
289.99 for brand new Crown Automotive front driveshaft from Morris 4x4 out of FL. Free shipping. And it's an easy project. Trans case skid plate removal cross member partial drop. Wiggle front shaft out. Already yanked it. Way less than an hours time.
Should get here tomorrow. Hopefully it is the fix.
And since the u joint looks good. For $137 they make a CV joint repair kit. I figure I can have the extra one laying around.
Anyway. Sorry for being long winded.
Take it easy