I just read a grip of posts regarding vibrations and still need some advice.
My story: While driving at about 50 mph in 4th my crawl box needle bearing seized which brought my tires to a dead stop and caused me to slide at least 50 ft. What I found was that the needle bearing on the coupler was seized and 5 of my ring gear teeth were torn off.
.............., had a shop install a new set of 5.29 gears and had them reuse my solid spacer(which are still being broken in).
when you installed your tcases did you dump 1 qt of lube into the front case shifter hole??
if not thats why your needle bearing locked up
.............. and were pro installed i wouldn't worry about that being the problem. it most likely is from the trans, clutch assembly or one of your t-cases. i hope that may help you. ![My Two Cents :twocents:](https://board.marlincrawler.com/Smileys/marlin/twocents.gif)
being installed by a "local shop" does NOT = a professional installation, there's a "offroad shop" near me that does gear installs for customers, i recently found out they dont have a bearing press and never have, they just "eyeball" the pinion and install what looks good
![Shake :shake:](https://board.marlincrawler.com/Smileys/marlin/shake.gif)
so what im saying is, CHECK YOUR PINION
make sure its not sloppy, also make sure your drive shaft is in phase, the bouncing you discribes sounds like a busted u joint or a badly out of phase shaft