[spdbrake]

Since I bought this car back Dec 2015 I chased a lateral vibration (shuffle) above 60 mph. Steering wheel shake + rear end L-R L-R (axial).

The car sat for approx 12 years (2003 - 2015) and had 892 miles on it.

My first thought get the tires and wheels balanced. Which was a no-go since they were 13 years old no one would touch them.
Changed tires from Goodyear F1 to M-T street comp 245/45R17 & 315/35R17. No change = N/C
Had them road force balanced. N/C

So started to change parts out and many were needed. Blown shocks etc..
In no particular order

Front end:
New Control arms
Ball joints
Poly bushings
Shocks
Repacked steering rack
Camber plates
Tie rod ends
Rotors
Calipers
Hubs / Bearings
Steering shaft bearings
Steering linkage, universals, support bearing, vibration reducer
Experimented with a shock style steering damper

Rear end:
Upper and lower spring perches
Springs
Full poly bushing set
Lower adjustable camber control arms
Shocks
Axles
Driveshaft
Rotors
Emer cables and shoes
Hubs and bearings
Diff attaching hardware
Sway bar bushings

Suspension alignment, experiments with corner weights and tire pressures.

During all this I had the wheels balanced two more times.
The last one I asked for the Oldest tire guy in the shop and to break the tires down and rotate them on the rim for the lowest weight requirement. N/C

I had already done Radial and axial run-out measurements on the rims and Pin drive hubs. Hub had less than 005" radial run-out. the max axial I could get on any rim was .030" at the bead seat which is pretty good.

I knew:
If I ran the car up on jack stands the vibration was present.
If I ran the car up on jack stand with front wheels installed on the back the vibration was present.
If I ran it up With Out wheels it was smooth. (No real rotating mass)

Then I started looking into replacing the wheels. Bolt-on this time. I spoke at Length with Bob @ Vintage Wheels and Scott @ ET Wheels.
Settled on the ET Classic V (Original Torq-thrust Look in 17X8 and 17X11) on the offsets I needed. I was almost ready to pull the trigger but thought "Maybe I could borrow a neighbor's BMW wheels to troubleshoot with". That fell flat as everyone politely declined.

I went ahead and ordered new Gorilla wheel studs in 12mmX1.5 then ordered a New set of Pin drive nuts from Trigo thinking if I sold the wheels they should at least come with a decent set of Nuts.
Installed those on the car. Of course N/C.

Then it hit me. Remembering my old helicopter days. A lateral rotor vibration (radial on wheel) manifests itself as a Vertical vibration (axial on wheel) in-flight.

I bought 20 12mm X1.5 -20mm long bolts from Mcmaster.
Removed the pin drive hubs from the car and attached the drive drive nuts to the hub using the short bolts. Then attached the hubs to the wheel using the Knockoff spinner.
Had the whole assembly road force balanced as a unit. Once done match marked the Hubs to the Wheel clock angle. (I even noted where each pin drive nut was located)

The car is like Glass now at ALL speeds.

There are some variables I don't have hard answers for.
Were the hubs really the problem?
Was it the large diameter inner wheel bore not getting the wheel centered on the machine?
The experience level of the Tire shop personnel?

I used House of Hot Rods in Mansfield TX for this this last balance. I must say their folks have their $hit together.