Ahhhh... now I think I know what your talking about!
There's a small "bolt like" plug actually on top of the passenger side axle tube, a couple of inches away from the differential... right?
A few years back, I remember someone else having that bolt (plug) leak, and that there were little, to no threads on it,
But, I can't remember if they "just" used some gasket sealer on it, or did something else,
But, whatever they did, it apparently held it in place with no more leaks.
The pics that I posted are of a Kawasaki rear, so, it's a good possibility that you have a Graziano rear end,
It's to my understanding that Club Car started with Graziano rears,
then changed over to Kawasaki somewhere in the mid 80's. (But, don't quote me on that!
)
So, No... it's not a newer style,
nor, do you have to worry about the one you have,
Graziano rears are made well... It's just a little bit tough to find parts for them anymore.
Hope this helps!
Note: anybody can feel free to correct me if my memory is "off" a bit!