4" Portal Bearing Rebuild Kit GEN 3 Portals Super ATV's 4” Portal Rebuild Kits contain enough seals, gaskets, and bearings to fully repair 1 hub. Sometimes you forget to put the fill plug back in before a ride and you get some crud in there. It happens. We make it easy to get what you need for your GDP Portal Gear Lifts no matter what version you have. Our seal kits get you all the seals you need, and our rebuild kits give you all the seals and bearings you need. It’s that simple.