Finally had some truck time this morning. Mounted the spare tire/wheel on the right front and took some measurements using a set of feeler gauges and my homemade runout gauge shown below. Apologies to HRL.

I don't think anything that I measured would cause the shaking in the steering wheel I felt. I was only spinning the tires by hand, so go nowhere near the 40 MPH I felt the problem at before. I did take the truck on some really smooth pavement and could feel a vibration at 20 mph if I had just one finger lightly on the steering wheel.

I tried shaking all the steering components while I had the truck off the ground and couldn't detect anything loose.

Here is my measuring device and the results of my measurements.
Attachments
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Last edited by Bill Hanlon; 07/24/2024 9:39 PM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.