I don't see any rivets and there is a nut on both the top and bottom. The top nuts are pretty rusted on, so since they don't appear to be bad so I will not mess with them. I did get the u-bolts on the short drive shaft chanced today. There is steel fitted plate on the spindle side of the shaft with a plastic washer and smaller rubber seal. Does the plastic washer and plastic seal need to be replaced if they are not torn? I did get new of the bigger rubber seal.