I got mine at the local John Deere dealer p/n R34812. It is a very common oring used on the expansion valve of many automotive AC units. I just picked up my new Victory from LGS today and immediately disassembled it using a 1/4" drive beam torque wrench. The take down screw came loose at 30 inch/pounds and it did have red loctite on it. I left the loctite on it and torqued it to 40 inch/pounds. I really don't want to use the oring because the tension may decrease as the oring collapses.