I purchased a used 1992 750 with 7,000 miles on it and found out about the need to lube the splines after I had already put new tires on it. I decided the next time I put on new tires I would check it then. Bad decision. The bike now has 18,600 miles on it and I just replaced the tires and inspected the splines. Red dust. The splines were completely dry. There is no indication that there has ever been any grease on them (or anywhere close to them, ever). I greased what was left of the splines and put everything back together. How long do I have before failure?