Issues with JKS 2.5" lift

[cehernandez]

I recently installed a 2.5" JKS lift kit on my 2004 Jeep TJ 2.4L (with 130k miles) which previously had stock springs. I'm now experiencing several new issues that weren't present before the lift, and I'm running P255/75R17 (Wrangler SRA 2017)

**New Issues After Lift:**

* **Vibrations:** The Jeep vibrates noticeably in 2nd and 3rd gear, primarily felt in the steering wheel.
* **Popping Sound:** A weird popping sound occurs when turning the steering wheel to the left.
* **Death Wobble:** At around 40 mph, hitting a bump triggers severe death wobble, forcing me to stop.
* **Speed Limitation:** I can't comfortably drive faster than 50 mph unless the road is perfectly smooth.

**Troubleshooting Steps Taken:**

*A steering stabilizer has been installed, which seems to help at lower speeds. However, it doesn't prevent the death wobble at higher speeds.
*My tires have been balanced.

I'm seeking advice on what might be causing these vibrations, the popping sound, and the death wobble after installing the lift kit.

 

[Duck Doctor]

Did you align the rig after installing the lift? Does the vibration you feel in the steering wheeling in 2nd and 3rd gear go away if you push in the clutch while going that specific speed? I suggest verifying that the front track bar bolt is tightened to spec

 

[cehernandez]

Did you align the rig after installing the lift? Does the vibration you feel in the steering wheeling in 2nd and 3rd gear go away if you push in the clutch while going that specific speed? I suggest verifying that the front track bar bolt is tightened to spec

I got an alignment done
No the vibration stays while I'm in 2 to 3rd gear or 10 to 30 mph but as I gain speed between 20 to 30 it softens.

 

[TheBoogieman]

Did you get the JKS adjustable front track bar too?

 

[CharlesHS]

While TJs are built similarly they react differently when lift components are installed.
Some Jeeps have no driveline vibrations with a 2.0-2.5" lift installation; others do and mine was one that did.
Several years ago I replaced the sagging factory springs on my '01 with 2" springs and immediately had driveline vibrations.
My interim fix was to do a 1" transfercase drop (washers between skidplate and frame rails) which resolved the vibrations.
When money was better I installed a SYE, removed the TC drop and purchased a Tom Woods DC driveshaft; which resolved the problem.
During the driveshaft installation I measured the rear differential pinion to driveshaft angles; they were acceptable at 1* difference (changed to 0* with occupants in the Jeep).

 

[cehernandez]

Did you get the JKS adjustable front track bar too?

Yes

 

[StoneCold]

I would try the transfer case / tranny drop for your vibrations.

Then I would check your ball joints and the U-joints in the driveshafts for the death wobble.

I had some vibes and replacing the drive shafts u joints got rid of them...a couple were obviously toasted...