My 1994 R1100RS was manufactured on 5/03/1993. When I had removed the Rear drive to replace the boot that got damaged I was in for a surprise. I all the tech publications I have seen there is shown a retaining clip between the stub universal unit and where it mates with the pinion spline. Well mine doesn't have that clip nor is there a groove to install one. My unit has the long unsplinded nose on it, did this design ( which is obsolete) not require the clip as I do not see any accommodation groove for a clip on either piece.