What worked well for me was to put a generous blob of GE Silicone sealant in the end of the rod that actuates the front output shaft. (The yellow arrow in the picture shows the place for the silicone..) You have to loosen up the pivot bolt in the shift linkage to create the gap for the silicone. Then only partially tighten it until the silicone is cured. Once cured, fully tighten up the pivot bolt. No more bad vibes......I did this right after a full rebuild of my case, so I knew it was good....NO more bad vibes!!!!