New vibration under accelation.

[Madmaxz]

Ok so this just started a few days ago. only really happens above 50mph and goes away around 80-85. but at 50mph+ if your on the go pedal it vibrates the floor/seat take foot off the pedel and coast it goes away. i have a the carriar bearing droped 1" and just tried it at 1.5" but no difference. the rubber around the bearing is busted up in one spot and dry rotted alittle but the bearing spins fine and the bearings in the bearing feel fine should it still be replaced?

If theres no visual sign of bad ujoints how do you test?

[joeniel]

Id say your right looking at the ujoints because that sounds exectly what was happening to my truck recently and I had all three joints done and now its fine. But I dont know how to test it. Maybe get under and shake the driveshaft, seeing if the joints move in a way they arent supposed to? Idn I'm no mechanic, lol.

[Madmaxz]

yea i tried to get the ujoints to move by hand pushing/pulling but cant get them to budge everything looks tight. guess ill have to get under it while someone shifts into drive/reverse see if they move.

[03_Turbo7.3]

easiest way to check ujoints is to drop the drive shaft, rotate them around and make sure they are 100% if there is any grab or stiffness replace them

[Madmaxz]

all the u joints are fine even the carrier bearing looks fine replaced them all tho. how much should it cost to get a 2pc driveshaft balanced?

i also read on a dodge forum if the vibration goes away when you let off the gas and comes back when you get back on it then the problem might be in the rear axle.. **** i hope not!!