So I was going to leave it alone, as the part that was originally broken on the retainer didnt seem to effect the seal whatsoever, but to get the seal out you have to take the retainer off. In doing so, I may or may not have f***** up the retainer, chipping many of the teeth off and whatnot :/ Mechanically minded friend said that it was easy to do. Just screw in, bottom out, ease out an eighth of a turn. Everything I have read says (damn near) the same. Questions: Every where I look about adjusting preload mentions doing both sides. I would rather not codswallop with the other side as well, can i just do the one side (drivers) and call it good. I ordered the god damn part blindly, not knowing that the two sides were different from eachother. I am new to subarus, think I am mechanically adept, but the part I ordered was listed as "differential side"..........just from memory, im pretty sure the differential dipstick is on the passenger side, and that would lead me to believe that the part I ordered is for the passenger side. Yeah? Are they interchangeable