Wife has a 2010 300 sportsman. We were out for a trail ride and the quad suddenly quits moving. Still runs won’t move. Pulled the clutch/belt cover and it has about 1/2 quart of oil in it….not water..oil. Removed the primary and secondary clutches and found a seal behind the secondary but it looks good. What am I overlooking ?? This thing has been a money pit since I bought it so I really would like to fix it myself. Thanks for any help in advance.