not a 'weak point', and I've never experienced severe leaks in the many I've driven - could be the rear seal, but check all the plugs are tight and the speedo cable is on
if you can scrounge up a used one with good gears and no leaks, easier to change than rebuild, and cheaper - newer will work, 64 is identical, and from 68 on they have synchro first, although there you need to get the yoke with it cuz the spline count changed, otherwise the 3 speeds are really the same trans from 55 to 70's or 80's
Bill
