2010 Polaris Sportsman 850 Service Manual, Page 140Get this manual
ENGINE 6Measure pump rotor clearance to pump cover plate with feeler gauge through the pump outlet window and compare to specificationMeasure shaft axial (end) free play and compare to specificationInspect inner rotor drive pin for wear or damage9Remove oil pressure relief from crankcaseReplace if debris has entered, or if oil pressure was outside of specified range