ZJ with drive train vib over 65 mph (seems to be stuck in 4H)
About two years ago, I purchase a 1995 ZJ, I6, 200k miles with the following:
4" Zone Offroad lift with upgraded Nitro shocks
Zone offroad steering stabilizer (replaced - see below)
Drop pitman arm
Sway bar disconnects
Energy suspension sway bar bushings front and rear
Rubicon express adjustable front upper control arms
Rubicon express heavy duty front track bar w/ heavy duty bracket Rubicon express rear track bar
Rugged ridge heavy duty steering kit (replaced - see below)
Advanced adapters slip yoke eliminator, new rear drive shaft
15x8 Cragar soft 8 wheels w/ 33x12.50r15 Goodyear Duratrac Tires
Midland CB w/ Firestik antenna
Pioneer CD player
New suede headliner
Last summer, we drove from Dallas down to Houston in the ZJ. We have some land deep in timber country and I wanted to show my son how to drive the ZJ in the sticky stuff. The Jeep performed awesome! However, I noticed on the drive back to Dallas that it would have an occasionally vibration at about 65+ MPH. Not to bad, but the interior trim would vibrate and cause annoying sounds and squeaks.
Since my son drove the ZJ as a daily driver, and we rarely got on the highway, the problem didn't really appear again. He took it off-road several times and it always performed great for him.
It started to develop a little death wobble and I had the local 4WD Parts shop replace the steering with a Currectlync Heavy-Duty Tie Rod System, new tie rod ends, a front hub assembly, and Pro-Comp steering stabilizer.
That got rid of the wobble, but I noticed that the vibration was back. Last weekend, we moved my son down to Nacogdoches, TX and the ZJ had that vibration all the time when over 60+ MPH. I was following him for a while in another vehicle and I noticed that the front drive shaft was turning. I had him stop and I got into the ZJ. I shifted the transfer case through all the gears (tranny in neutral) and back to 2WD. I then drove for awhile and the vibration was still there. Got back into the other vehicle and watched as he drove, front drive shaft still turning.
So, it seems that the ZJ is in 4H. I could understand a vibration in 4H at 60+ MPH. But, where do I start on fixing the issue - especially since it is in Nacogdoches and I am in Dallas... I will have to work on it away from my garage and in a parking lot.
Thanks for any and all help.