W123 vibration - engine, propshaft mounts?

[RomanTotale]

Hi folks, my 84 280e has a strange set of vibrations evident from about 2000rpm up to about 60mph in top gear. It's not a constant vibration and not one that makes the car unusable, but one that creates a background hum that goes in and out - the nearest thing I can describe it to is the sound of a multi engined aircraft with out of phase props. Any ideas anyone?

I was thinking my first job would be to check engine mounts and propshaft rubbers. Are there any other such rubber fittings that could be replaced?

 

[television]

The engine mounts do solve a lot of problems, when the have collapsed the whole drive chain gets out of line to the point where the whole car can shake as all of the drive components like prop UJs are working to the extreme. they are 22 years old

malcolm