Stan;
One other question to consider, which was hinted at by another poster. Is it possible there has been a bit of clearance on the right side ever since you had it, even when it was new. It was tight & on face & you just never particularly noticed it. After all these years of use, maybe it only wore about a .001" in the joint but that was just enough for you to notice the looseness & upon giving it the real look over you found this .004 on the right side. Maybe it left the factory with around .003" but you just never examined it that critically until you felt that play.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra