Dittos on Samian4 concerns about checking the flex discs. We have had a worn front disc break, hit the transmission tunnel hard enough to set off the airbag. Please check the discs visually and physically by twisting the driveshaft and observing looseness. Pay attention to both end of the driveshaft. Fronts have been our main wear item, but both do wear and cause problems that you descibe.
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