Interesting wear pattern on the big Oring on the drive flange. About 50K miles ago, I neglected the spline lube ritual too long and by the time I got home from the east coast, about 20% of the cross section of the spline ribs were worn away on both final drive and drive flange. Have faithfully lubed every 10-12k miles since then, but the damage was done and the constant beating from the extra slack in the splines have worn away another significant percentage of the cross section and perhaps only 20% remains. Took about 50K miles to get to this condition. Anyway, bought a pristine final drive from Pinwall (they inspected the splines for wear and assured me they were in excellent shape) and a drive flange from ebay and will be replacing them in a month or so....the car tire will have some 28K and due replacement. There have been several photos posted of splines, but I suppose I will post my worn ones when I do the replacement.....but I thought it was interesting the wear on the oring caused by the extra radial slack in the spline. I guess the moral of this story is, lube the fricking splines, loosen the 4 final drive bolts upon reassembly, don't worry about having to replace splines as soon as wear is detected, bla, bla, bla.....
