Can it be worn wheel bearings?
The 83 w126 mentioned above is mine.
I have had this problem since I acquired the car. I have changed most of the undercarriage components including tie-rods, steering damper, ball joints etc and there is no more element of play. I had previously performed on car wheel balancing on the original rims with some improvement, and recently changed the rims and tires (Simmons 3-piece 15", 225/60/15).
I now find that the vibration is inducible at 140km/hr and goes away after 150km/hr which is similar despite previous rim/tires/various balancing manouvers. However, it is more pronounced when going downhill or pressing on, and hardly felt when uphill or cruising gently.
I have recently developed increased road roar and have pinpointed it to a worn out bearing in the left front wheel which I will be rectifying soon. Could a worn bearing translate to some play in the wheel causing this vibration? Alternatively could this be drive shaft wear?
1983 w126 280SE - daily drive
1983 w123 200 - sold