I have replaced 3 right rear inside boots and it looks like another one is leaking grease. I even had a boot melt. I have areas where I do 45-50 mph for long stretches at a time. Or I might trail ride about 30 mph for 30-45 minutes. These rides are on pretty warm days. The RR inside CV joint gets hotter than a fresh ****** fox in a forest fire! The conclusion I came up with is the motor gets extremely hot in those conditions and the CV joint and being only foot behind the motor that gets all the heat off the motor. The left rear gets pretty hot but not like the right rear. My wife's Sportsman 800 rear CV joints barely get warm but the motor is far ahead of them. Guess I am going to figure out some heat shields or start taking more rest stops. Any ideas or suggestions?