Hey all I have run into a problem with 3 different Polaris Rangers with oil leaks at the oil filter. I have checked for debri on the sealing surface, there is no gasket or o-ring material on the sealing surface and it only happens after 20 hours of use. I have tighten the filter using an oil filter wrench but at around 20 hours it leaks again. I am told that the 800 cc engine had some oil pump pressure relief valves will stick, causing seal failure. Anyone have any input on this and what is the fix?