Outer Limits 4x4 Board

I would check your swivel housing bearings if everything else is ok as you say, disconnect steering arms and check for tightness through the central part, if this is obvious replace bearings this is what motor bikes get when steering head bearings become worn and they get the "tank slaps'" usually a ...

I have a 5inch lift, running tough dog adjustables and 5deg castor plates, no vibes drives great and been like this for 2 years and no probs, do have part time kit also.

The HDJ80 was the updated td cruiser in late 95 through till 98 they have the 1HDFT engine in GXL and Saharas auto and manual

I would just replacing the oil with lubramax power steering and then bleed system like the last guy said.