On my 450G theres some pretty new,little if any wear but I dont have the measurement here, Berco tracks that were on the machine when I got it it seems theres 2 links that are a few feet apart that have seized.They are free from any crap that might cause this I gave them a heavy shot of PB 2weeks ago and they have been sitting since.Ill be back up there thursday and would like to address this issue.Any thoughts on what to do?