300 ce

[allynne]

Hi folks i'm back again with the same problem, vibration, so far i have replaced the springs,dampers,front prop coupling, 2 new tyres on the front, the car has spent the best part of 2 hours on the ramp at my local mot station being inspected and yet they found nothing worn, the only thing they found on the rearmost section of the propshaft it looks as if a very small balance weight has come of, would this make the car vibrate and make a dull drone....please someone help its driving me insane.

 

[bigt]

vibration

Yes it could. All fast rotating shafts have to be balanced, particularly hollow ones as it is almost impossible to get the wall thickness absolutely uniform during manufacture. Bearing in mind your prop shaft can rotate at very high speeds, they have to be dynamically balanced by the manufacturer. An out of balance prop shaft can set up harmonics which sounds like a dull drone and sends more of a resonance than a vibration through the car. If you are shure that the alledged missing piece is a balance weight, then that is almost certainly the cause.
Unfortunately, you cannot weld a new weight on as it has to be calculated by a dynamic balancing machine not dissimilar to what they do when your wheels are balanced, so you will need a new or second hand one, but having said that there may be specialist engineers who will undertake this but it could be expensive. It is better to remedy this sooner rather than later as harmonic vibration is deadly to UJ's and bearings.