The upper liner is definitely showing signs of wear and is more than likely the cause of the knock. The needles should be shiny and not blue or purple colored which shows signs of heat. Vaseline can be used to hold them in place and it washes out as soon as the motor starts. Grease doesn’t. A pair of tweezers helps to get them placed properly to. I think there are thirty needles used in these bearings and each one of them has to be accounted for. Dropping one into the motor and not noticing it is a recipe for disaster.
