vibration

If your vehicle makes a clunking sound when you shift from D to N to R, that is a sign of bad U-joints. My 69 Dart did that for years and I didn't know it was abnormal (was a dumF kid). I finally got a slight vibration right at 60 mph on the highway that went away above that. I pulled the driveshaft and found one U-joint totally rusted inside with a lot of slop. That tells me it has to be pretty bad to notice.