I put the trial-gear accordian style breather on my rear end and now I am reconsidering. My rear end has been leaking out the companion flange for a while and I think its the seal but I think the leaking is also due to excessive pressure. When I removed the filler bolt it sucked in a whole bunch of air. I plan on getting some hose and running it up higher and putting a filter on the end. I don't trust the stock breathers eithe(at least for keeping junk out).