I personally dont like to run a cover on my spur, I feel that when something does get in there it just stays trapped and keeps getting run through the gears, not only that but none of my race vehicles have a sealed spur. but my real question is does anyone just run without a cover on their center drive shaft? I always have a small rock or two when I change a battery but I just pop it out, but has anyone gone a very long amount of time without one? have you worn almost completely through the shaft? thanks, just curious?