(not)Good Vibrations

I have noticed the past several times I've driven my white Jeep that I have a strange vibration. It seemed like the rear drive shaft so I checked the u-joints. One was a little sloppy so I replaced it. No good. I then ran it up on jack stands and it appeared ,y rear drive shaft might be bent a little. I took it out and just used the front axle to drive around and didn't feel any vibration. I took a front CV drive shaft out of a Cherokee and had it shortened to fit and bought a new yoke. With all the new stuff my vibration seemed worse. Ouch. I started wondering about a bad bearing in the transfer case. I've never had my Dana 300 apart so maybe something in the output shaft area. It only does it when it is loaded. Either speeding up or slowing down it vibrates. Just sort of coasting along it is very slight. I'm wondering if the added weight of the CV u-joint makes it seem worse?? Any idea's before I start draining fluids for exploratory surgery?

 

check oil in diff? pinion bearing?

 

bent rim or bad balanced tire...I had older tires with good tread changed them and vib went away....

 

If you're going to run a CV shaft, the angles have to be set correctly. The end with the single U joint must have not more than about a 1 degree angle. This will probably require shimming your rearend.

I can't find any info in your profile on what kind of Jeep you have but since you mention Dana 300 t/c, I imagine 80 or later.

 

Correct. The pinion needs to be pointing directly at the T-case output in order to run a cv style shaft.

 

I have it shimmed but maybe not enough. I will check that but it vibrated before I changed drive shafts. It act/sounds like a bearing. Driving with the rear drive shaft out produces no vibration. I will check fluids and angles before I take anything apart. Thanks for the idea's. Oh, my white Jeep is on a 72 CJ-5 frame. Centered Dana 44 out of a Jeepster. T-176/Dana 300.

 

If you think it's a bearing, try shaking the t/c output and rearend pinion up and down.

 

Well, remember that without a double cardon joint (Using just single joints) the angles on both ends of the driveshaft need to be about equal or you will get a vibration.

Also on your original shaft, the yokes should be clocked the same on both ends or you get vibration.