I have a vibration coming from the drive train and i have replaced the u-joints and it sounds like the vibration is coming from the rear end. It does not vibrate all the time just when i accelerate sometimes. it does not do it when i deccelerate. i'm not that mechanically inclined so i was just wanting a little advice if you have any. Thanks.

 

Could be a carrier bearing.You may not evenhave one.
2wd or 4wd? Long bed? Ext cab, 4-door or regularcab? Lifted?

 

It is possible u-joints got messed up on install. Did vibration change any with u joints? What is the condition of engine and trans mounts? What speeds does it vibrate at? manual or auto trans? What gear are you in when it vibrates? overdrive? If you toe the brake with your other footwhile your still accelerating does vibration stop?

 

It's a 4WD automatic regular cablong bed not lifted with 175,000 miles on it. I bought it from the bank a couple years ago as a repo so I'm thinking it has had a rough life. The motor and tranny runs fine and it vibrates in overdive and third gear going anywhere from 40 to 65 mph and I'vetried tapping the brake when it starts to vibrate and that doesn't do anything.I have replaced the u-joints twice and it still does it. I was thinking it was a bearing issue but was not for sure. Any other comments will be helpful. Thanks!

 

U def wanna check those mounts. I imagine even a worn out mount could possibly cause a vibration if it throws your driveline angle off. What about the condition of your shocks?

 

I've never replaced the shocks and none of them seem busted or anything.

 

Something else to check isbent rims. My 2000 3/4 developed a shimmy and that was what it was.

 

I'm a Jeep girl, this is my first truck and I know its leaf verses coils BUT like the guy above said a bent rim, unbalanced tires, can cause some serious shimmy. Maybe check steering stabalizer (although I think thats just a bandaid to a bigger problem).