my buddy bought a 78 c30 and we noticed that the yoke on the diff moved alot more than it should. we pulled the cover today and it was a open carrier, but instead of seeing gears in the little windows, we saw a big ass spring. is this a detroit? lockrite? or what? also on the yoke movement, the backlash is correct, but what is causeing the movement? is it the splines on the axles wore out or is the locker something to do with it? it doesn't look normal.