Drive line noise mystery? Solved

[alborz]

Yes I was right
The guy at the shop had. Put rear rear spring leaves on the front and frornt for rear.
The slight bow shaped rear rear spring would make the axle to rotate upward and making the yuke inline with enteraxle drive shaft.
Since he put rear spring for the front there ewas a mis alignment to both drive shafts and since the drive shafts and yuke wee rotating at different speed so that f.. noise was traveling up to the front and heard in cab plus unusual vineration.
If you read this thread entirey you’ll understand what I have been through. All because an hourly guy made a simple mistake and the manager refused to review their work.