Alright I've tried a few things and it's still vibrating and its at about the same speed no matter what I do. I've flipped the shims and adjusted the shackles to no avail.

 

When you rechecked the angles, after you flipped and such, what were they?

 

I didn't have time to check because I had to go work. But the pinion angle was slightly below the driveshaft angle.

 

Do ya'll think it could be the front driveshaft causing the problem and I've just been focused on the wrong things this whole time?

 

Alright, took out the front driveshaft. No difference. I'm going to try putting the driveshaft that was in front in the back and see if that helps any.

 

Put the other shaft in no difference

 

Pull the rear. Leave the front and see if it vibrates. Also get those angles for us

 

Last time I drove with just the front (just moving it around a little) the wheels felt like they were hopping when making sharp turns

 

Was this recently? Myself and others have driven a FWD XJ and I don't recall hoping. Have you checked the front u joints for discoloration like grey.

 

Check to make sure you are not missing any weights on the drivesahft. I'm using a front 33" driveshaft out of a ZJ for my rear. I have Zero issues, but I corrected my opinion angle when I swapped in my rubi 44 by welding my perches on at the proper angle. But my front shaft is missing weights and vibrates like my ex's toys. Also, at 133k+ miles, it wouldn't hurt to price out a rebuild by a driveline shop. They'll balance it too.

 

When I putting in the sye I had to move my jeep and I had already taken out the rear shaft so I put it in 4 part time and drove it up the street did a u-turn and came back and it felt like it was hopping some or maybe just grabbing. I don't see discoloration on either driveshaft.

 

I don't believe I'm missing any weights because I tried both driveshafts in the rear. I could just be really unlucky and have 2 bad shafts. Also, I feel like there would be a change in the vibration by taking one out if they were both unbalanced. I think I'm going to try a zj shaft. I'm starting to think mine is a little short and maybe that's making it unhappy.

 

The shafts are designed for about 1" of gap at the splines. In my experience, when you start extending past 1.5" or so the splines lose engagement and start to get a sloppy and induce vibes. In the first pic the splines look like they are around 2-3" of gap, way too much

 

Yeah that's what I'm thinking so I'm going to go to the junkyard and get a zj shaft because they are a couple inches longer

 

measure from yoke center to yoke center and post it here, I'll see if I have a matching number