Vibration in floor 1992 Buick Roadmaster
Hi there - yes, this is a driveshaft issue. It could be a worn u-joint (front) (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-universal-joint-u-joint), or a worn driveshaft bushing in the transmission tailshaft housing. Either of these would cause loose motion and vibration from the driveshaft such...