96 XJ with new RE 3.5 lift

Just installed the Rubicon Express 3.5" lift on my 96 XJ. Excellent soft ride, excellent lift kit. Put new leafs in back....

Now on accel and decel mainly- sometime while driving it has a good vibration. It seems like its coming from the rear driveshaft.
Do I just need to get a SYE and new driveshaft for the rear? What do I need to touch on the front shaft? From the searches ive made, i was confused about what the front and back needed. thanks for any help.

pics?

You can try a t-case lowering kit, if you cant afford a SYE right now, might help but not typically a permanent fix

You should be ok with a T case drop (1"). My 3.5" RE lift was almost 4.75" when it was new, but it settled to around 4" before I added my winch bumper / winch. Now it's down around 3.5" ish. I had a small vibe at first, added the T/C drop and it went away. That's before it settled. Some will tell you that you must get a SYE. If you have the extra $$, go for it. I've got almost 5000 miles on my lift now with t/c drop and no vibes at all.....

This is the beginning of a long effort. SYE will do nothing by itself, you will need angle shims, and a new CV drive shaft too. Go with the TC drop until you can do it right... and do it after you've settled on your final lift height.

Check your DS angles with an angle finder. If they are close, you probably don't need to do anything. However I found that a Rustys 1" drop crossmember helped mine after listening to it growl for years. Oh, and lube the crap out of your slip yoke.

I had the same noises with my 96 after lifting the same amount. It affected my acceleration as well. And the rubber boot off the back of the TC was no longer attached to top things off. It was obvious that the DS angle was too great between TC and rear pinion so I did the simple TC drop and shimmed my rear axle 3 degrees. That brought the DS back into its comfort zone and, with the weight of the tools and gear I carried around normally, eliminated the issue entirely. Without that added rear weight, I feel that perhaps a 4 degree shim would have been a better choice. TC drop was simply 1" square
.120 thick tubing. I welded a nut to the threaded posts and then just backed them out after PBing them. 40k miles later and still no issues with the above fix. Don't forget to reposition your track bar (see GO Jeep write up for that) and consider making or buying longer links up front to reposition your sway bar. Maybe your lift package already addressed those things so forget that part if so.

I have the same Jeep the same lift and the same problem. Been racking my brain in order to find out the problem is, thanks for the info.