This past weekend I was doing a brake job on my nephews 89 Pathfinder, but had to stop due to a part I'd never seen before. While trying to remove the rotors I found a "lock ring" and I do not have any tools to remove it. It's a dowel or pin driven ring behind an automatic hub cover and a number of misc. washers/spacers. Will I need a special Nissan only tool for it, or can it be found elsewhere? I've never seen or dealt with anything like this before. Does it do the same thing as the castle nuts do on most cv shafts? I'm assuming if it is similar to the castle nuts in function, then it will take one hell of a breaker bar to free it. Is there anyhting else behind it that I should worry about, or is it just the bearings and I'm done? Any help would be greatly appreciated. Even the local parts stores look at me like I have two heads when I try to explain it and ask for a tool to remove it.