Friday greetings to the List,

                I'm having trouble locating an O-ring for the diff on a '91
auto box part # 010 409 259A, dealer says its NLA. Its dimensions are 3 x 78
and I presume that's in mm. Have checked with various venders with no luck
yet. I did find one at McMaster Carr but not sure if the dimensions for the
O-ring diameter are inside or outside. Does anyone have a clue,I don't have
an etka? I'm hoping its an inside diameter since that's what McMaster sells.
Also how critical is it to replace this particular O-ring. I'm going to be
changing out the 2 pinion seals that reside in a diff housing separating the
two trans fluids and there's 2 O-rings in this assembly that look like they
should also be replaced. Its one on those that's gone to vanagon heaven.

Thanks

Rick