Dumb and Dumberer

[rover3l]

Got the Q up on ramps today to inspect possible sources of drive line vibration. Noticed that there was underseal on various parts of the drive shaft. Thin coating in parts and some random spots. Dumb question is could this cause the vibration

I couldn't get enough clear access to clean it all of. I think I need it to go up on a 4 post lift and to clean it with white spirits

[Nathan]

Could be, I know I've had just one little piece of mud stuck on the inside of a wheel and it vibrated badly enough to make me think I had broken something in the suspension. How severe would you say the vibration is?

[rover3l]

It is mainly noticeable on a smooth road as an irritating background vibration that can be felt through the structure of the car. For example you can detect it slightly through the seat and the rear view mirror vibrates so that the view through it is fuzzy

[maxnix]

Try cleaning it with a solvent and you may well be pleasantly surprised.

I guarantee it wasn't there when the factory did their balance.

[DAEDALUS]

It could reasonably add up to a couple ounces if it's half the surface area of the drive shaft. Not a large moment of inertia compared to, say, a tire, but it's spinning a lot faster.

[rover3l]

Drive Line vibration cured - cleaned all the rogue underseal off the drive shaft and it now runs very smooth