I have been reading through a lot of threads and there seems to be some confusion or perhaps misinformation on the SADS couplings for early Previas. I have a 1992 and was wondering what needs to be done when these fail? There was a discussion that the couplings can be replaced, but another person was adamant that they weren't replaceable, but that a later model shaft needs to be found from a junk yard, is this true? Is there still an OEM Toyota coupling kit available? Is it only used on the later shafts? If anyone can please clarify this for me, I would greatly appreciate it. Thank you.