Driveline vibration

I have a new vibration on my 87 XJ that seem to be comming from the rear drive shaft. It vibrates on acceleration and steady cruising, but NOT when decelerating. Most bad U-joint will vibrate when decelerating, in my past experience.

I replaced the u-joint at the axle end of the rear drveshaft a few months ago and every thing was smooth. The other u-joint seemed fine at the time. Could the front u-joint cuase this type of vibe?

Thanks-----------Dave

Since you have some pretty good sized meats on your jeep, have you checked air pressure, thrown wheel weight, or excessive mud buildup on the inside of the wheel rim. Have you checked the other (remaining) u-joint for binding or slop? Bolts tight on the axle flanges. Have you dinged your rear driveshaft or checked for a lost balance weight on your driveshaft? Transmission mount still ok? Anybody else?

I was going to say, wheel out of balance, or drive shaft out of balance. many diferent things cauld cause those.