I believe misalignment is the common problem on these. I think we talked about it before, but my 33SW evidently does not have the driveshaft modified, and it was a Ford problem. I have read about these issues on F550s that are not modified into motor homes too, so it is most certainly a common Ford problem. My service writer didn't know ANYTHING about cars, so was not able to communicate to me what was wrong and what they did to fix it, but I have seen lots of F550 owners reporting driveshaft misalignment issues on the internet.
