Drive train noise and vibration

[Barney Eaton]

My neighbors son has a late Chevy Caprice with the 350 V8......same car/engine as the late Roadmasters.......so I am asking the experts from Buick.

Here is the problem and what has already been done in an attempt to solve the problem.

 

Problem.......noise/whine on deceleration with no load...coasting.  In addition a constant vibration starting around 50 mph and up 

* Pinion bearing replaced

* New Moser axels and bearing

* all 4 wheels/rims straightened  (20 x 8 & 20 x 10)

* New tires  and road force balanced

* 3.5 in aluminum drive shaft balanced and new Delco U joints

* Transmission rebuilt less than 2000 miles on it, tail stock yoke bushing is new.

 

What are your thoughts/suggestions

 

[old-tank]

Try a different known good drive shaft.

[avgwarhawk]

Sounds like my 88 Monte Carlo.  Vibration straight out of the dealership.  Pinion replaced. Solved that horrible thumping.  But...still had a constant vibration at highway speeds.   New wheels and tires installed.  No joy.  However, found  a drum was not balanced from the factory.  

[60FlatTop]

Double check the pinion. Then check it again.

Bernie