My 94 Grand Cherokee that I just purchased as a restore porject, has a vibration only under load at 65-70 mph. I removed the rear drive shaft and foudn that the rear joint was seized. Replaced that and the vibration got 90% better but is still there. The front joint felt fine, flexible and no play. Pulled the bearing caps and all looked good.

Contemplating pulling the front shaft to isolate but was wondering if anyone had the same symptoms.

Do a search for "Death wobble" and see if you experience those symptoms. If that's the case (front end shake at or above about 60 MPH), I resolved it in my '94 GC by replacing the steering damper (a shock absorber for the steering) and the track bar. I'd start with the steering damper as it's pretty easy to replace and not very expensive (check other postings for a good name brand).

Do a search for "Death wobble" and see if you experience those symptoms. If that's the case (front end shake at or above about 60 MPH), I resolved it in my '94 GC by replacing the steering damper (a shock absorber for the steering) and the track bar. I'd start with the steering damper as it's pretty easy to replace and not very expensive (check other postings for a good name brand).

Thanks for the reply. Actually I had some progress on this yesterday. Pulled the front drive shaft and replaced the front u joint on it and it solved the issue. ( had slight play in it )

Now I am going to move on with dealing with the transfer case :banghead: , its a NP249 and has the "crow hop" when parking it. Whiel some people say this is normal :lol: I say it aint :nono: . The Viscous coupler is shot. I found a guy in CA who has rebuilts VC's for 200.00
http://stecouplers.com/recharge/modules/cjaycontent/index.php?id=9 (http://stecouplers.com/recharge/modules/cjaycontent/index.php?id=9)

Warrantied for a year, but I hate to get in this loop of rebuilding it and then maybe it goes bad again. Contemplating replacing it with a NP242 but that is expensive too but likely to outlast me in this lifetime. ;) Ah what to do what to do. Rockland Standard Gear has the change over unit for 950.00 plus shipping and a 200.00 core charge that they send a call tag for. Thought about going to the bone yard and getting a 242 and changing it over myself.