My dad has a 2002 Pantera 2-up 600 efi. It has what I beleive a 5/8 track on it, So I studded it with a 96 .875 studs about a mounth ago. I took it out for a test drive tonight on our fist 2" snow of the year and when ever I went over the slightest bump or really got in to it, it sounded like something was rubbing on either the tunnel or something. Any time the suspension would give a little I could feel the vibration on my feet. What could this be? I don't see any where where the track is rubbing, I also had a friend push down on the back and I still couldn't see where anything would be rubbing. It sounds like the lugs are hitting somewhere or the clogs on the track are rubbing somewhere. Please, any suggestions would be appreciated, It is a brand new left over sled and don't know why it is doing this.