Inconsistent Vibration at 90-130kph

[TheGodfather]

Significant vibration in footwell and in steering wheel at speeds of 90-130kph. Sometimes the vibration ceases for a few minutes when driving over small cracks in the highway. Almost as if some suspension componen/bushing etc is being jarred into the "correct" position. Should we rule out a simple balancing issue?

Not sure if related: I am also getting popping noise from the front end when turning, and over some bumps/dips. If I rapidly turn the wheel while parked, there is a popping/hollow type noise that sounds "loose."

Both swaybar end links were replaced last summer, as well as the PS outer boot, and the whole DS axle assembly. The noises I am hearing do not resemble what I heard when I had bad endlinks last year. Though I guess I can't rule it out entirely.

There is axle grease on my wheels. Boots are intact. It seems the grease has been squeezed out, perhaps a loose clamp, or it was overpacked. Could low grease be the culprit? I imagine significanly low grease will cause balancing issues, but intermittently?

All of these symptoms only began to occur over the past quarter, and not around the time of the above parts replacements.

I am taking the vehicle into an indy today to figure out whats up. However due to the multiple sysmptoms and the general difficulty of diagnosing suspension issues, I was hoping you fine folks could give me more ideas I can discuss with the mechanic.

Thank you all in advance for any input.