vibration at 45mph

[ram4x4]

My truck has started to vibrate from the rear end around 45mph. . I am thinking the journal bearing is most likely the problem however i can not find the part in any stores do you guys have any ideas? anything else I should look at?
of course it could be a bend drive shaft.

[camoit]

have your tires balanced. And check your rear shocks. After that you can look at the drive line. Or you can crawl under and look at the center support Bering. They have a tendency to have the rubber go bad from oil.

[pennyman1]

4x4s don't have carrier bearings - a bent driveshaft or a bad u-joint, even a misaligned axle can cause the vibration. If it is lsd, change the diff oil, in fact change it anyways - its most likely old and bad.

[ram4x4]

Thanks for the replies guys! I finally got under the truck today, grabbed the drive shaft and it shuck like hell! the bolts that hold it to the rear end had backed out(scary)! So anyway I tightened them up and all is good! BTW I had balanced the tires, replaced the diff oil, and shocks just to find that it was a loose drive shaft! Anyway it was good to go ahead and do all that stuff anyway, it was way over due.