Using a 1/4" nut driver to seat the diff o-ring is the perfect way to set it place for installing the gear pin and spider gear.
Then a trick that I picked up from Yannik for the perfect amount of diff fluid. After the gears are installed fill the diff with fluid (paying attention aiming the fluid in the four corners at first) all the way up to the top of the gears. Then add the top large gear ant let the fluid settle. Now take an allen wrench and scrape the excess off of the top keeping the wrench flat across the diff case. This will leave the perfect amount fluid in the case. Now add the gasket and install the ring gear to the diff case.
Until next time
