It might be hard to see hear, but Don at Roberts Body Shop did a nice job at welding the spider gears in my extra third member that I got off of Ebay. The differential came to my house in a Kitty Litter Box wrapped in a billion layers of clear tape and my mom could barely carry it into the garage. I think this differential must weigh like 60 pounds atleast and it looks tiny. This thing locks up great but I have a normal open differential that works great that I will put back in during the summer for street driving. I would advise doing this to any hardcore off roader who has a vehicle that just goes off road or only goes off road at certain times of the year. This creates excessive wheel hop on the road in tight turns because both rear tires are always spinning at the same rate. This will greatly increase traction off road though in thte mudd and while flexing or going through things at odd angles.