How often do you guys change the primary spring of your heelclicker kit?I've had clickers in my 98 SRX for some years now and the other night when I was out I noticed that the sled didn't feel quite right and wasn't revving out to the 8400 like it always did,of course the conditions were less than optimal but still I'd like to know if you guys have a regular change interval that you stick with to keep the clutching dialed in.