make sure the center bearing insert is installed correctly.... it has to go on before you put the center diff togther,, if not you will blow the bearing out or break the clutch bell... the stock clutch set up is soft and will wear out fast... the shock problem make sure the bottom cap is tight i had to chew mine up with plires to get it tight..... dont know about the hinge pin cover..... tighten the wheel nuts..... i lost one also cause I didnt tighten it what is wrong with the stock filters???