2002 YAMAHA XVS650 Wheels Problems

ON THESE MODEL THE SHAFT ON THE FINAL-DRIVE GOING INTO THE REAR DIFFERENTIAL IS NOT OILED NOR HAS ENOUGH GREASE TO LAST OVER 10K MILES. I HAVE HAD THIS BIKE SERVICED AT EVERY SERVICE INTERVAL AND GREASING THE SPLINES IS NOT IN THE SERVICE. NOR CAN THEY BE GREASED WHEN THE TIRE CHANGE IS PERFORMED WITHOUT HAVING TO REMOVE THE 4 BOLTS THAT HOLD THE DRIVE SHAFT IN THE COVER OF THE DIFFERENTIAL. MY SPLINES STRIPPED OUT WHILE TRAVELING AT 70 MPH ON A HIGHWAY CAUSING ME TO BE STRANDED AND ALMOST BEING RAN OVER BY THE CARS THAT WERE BEHIND ME TRAVELING THE SAME DIRECTION DUE TO THE BIKE LOOSING SPEED AND SLOWING DOWN VERY QUICKLY. WHEN I TOOK THE BIKE IN TI BE INSPECTED THE SPLINES WERE BONE-DRY AND THE PART THAT HAD STRIPPED WAS ON THE PARTS DIAGRAM BUT DIDN'T HAVE A PART NUMBER SO I COULD...