Inliners International Forums General Discussion Drive Train drivetrain vibration

If it is happening at a certain road speed even when trans is in different gears it has to be a rotating part behind the transmission output shaft. I worked on a friends Buick several years ago that had a similar problem and it turned out that he had the wrong u joint in his transmission output yoke allowing the drive shaft to move off center. The caps were the right diameter but the side spacing was wrong allowing the shaft to move off to one side at speed. Installed proper u joint problem went away. I would start at front u joint and check everything to rear tires until I found it.