How to finsh the steering play when drive high speed rining

Warped brake rotor usually cause high vibration at high speeds. But you can also feel it at lower speeds. But bad ball joints and tie rod end will cause vibration at high speeds. Ball joints will pop at pot holes, sometimes. Tie rods can be felt in the steering wheel at a stop. Move the wheel slightly to the left and right, you can feel/hear a tap as you turn it.

Out of balance wheels, shifted belts on the tires, loose steering parts can cause a shimmy while driving. Also, if the rotors are warped and the pads are stuck on the slides it will give you a brake pulsation that can be felt constantly even when you're not on the brakes.

Out of balance tires, or tread wear, or you hit something that has miss aligned your front steering system.

There are several things that cause low speed thumping if rear differential has been service or in need of they require a specail additive 4 ounce limited slip lube aftermarket grease doe not work . 2 nd if it is a hard turn steering in against steering lock alignment issues caster out of specs.

sometimes pulsating feeling comes from the rotors being warped and thepulling may be a badcaliper

One thing I can think of is that the steering gearbox adjustment is too far from the pinion and needs to be tighter. But then your mechanic would have known this and reset it. Only other thing could be that you have the incorrect backset in your front wheels and that would make the vehicle squirly at speed. That happened to me when the wheels I stuck on my vehicle were outset too much. Other than that, only other thing is there is no toe in on the front end. Without a certain degree of toe-in, there's no drag at all and the tires will flop from left to right at will.

Vibration from about 40-60 mph is usually attributed to wheel balancing, but the onset when you hit a bump seems to indicate play in the steering linkages (tie rods etc) or suspension members and stabiliser bar rubbers but you had that all checked out, that brings us back to the wheel balancing.

Lifting a vehicle changes the roll center. The higher you go the more unstable it becomes. I'd replace the shocks and steering stabilizer (sideways shock on steering linkage). Use the best ones you can afford. In an 84, I'd also suspect that many of the suspension bushings may be a bit worn. Those and all suspension linkage ends as well as ball joints should be checked for wear.

1. out of balance tire because it sounds speed spacific.
2. worst of all! Loose lug nuts or possibly loose spindle nut. (you will need to lift the wheel off the ground to tell)
3. worn linkages i.e. ball joints, steering linkage, anything that would allow play in the front wheels.

you might think its tight but its not. it could be worn on the inside where the gears are and never know it. i would change the pitman arm soon