driveline noise

[LEN_LEEB@xxxxxxxxxxxxxxxxxxxxxxx]

     Alberto asks:
     snip>>>>...At 40 mph, on a neutral or trailing throttle, a very distinct 
     and noticable vibration envelopes the car.   The origin of the vibration 
     seems to be the rear end and there is a noticable noise although it is 
     different from the noise that occurs at 70 mph.  This vibration occurs only 
     at this speed, and in second, third, or fourth gears.
     
     Sounds like a U joint to me.
     Only real way to check it is to remove the drive shaft, BUT MARK IT SO YOU 
     CAN PUT IT BACK THE WAY IT WAS! You want to preserve its balance.
     Once the drive shaft is disconnected, rotate it in your hand to check the 
     joint. You can feel it if it is bad; it will have a "lumpy" feeling to it. 
     If any rust or other dust pours out of it, replace it. the Alfa U-joint is 
     too small to have a grease fitting on it, so it only gets greased once in 
     its life. with 100K + miles on it, you should be grateful for such long 
     life!
     Len

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