I'm tracking down sources of rear end noise in my early '74 260Z. So far I identified a loose stabilization bar link. I also noticed while the car is in motion that the threaded rod protruding out of the top of the right rear strut has some minor movement associated with it while the driver's side one does not move.  The three bolts securing the top of the strut are properly tightened. As far as I can tell, the strut's upper end is held in place under spring tension. Is there anything I can (or should) do to keep it from moving around? 

Note that the struts and springs were replaced not too long ago but by the same monkey that was riding around in the trunk.

Maybe you could take the strut apart.. normally the threaded rod should fit perfectly in the hole from the top plate of the shockabsorber assembly, maybe it's wearied away from all the movement..  Be careful with the spring tension, use a good tool for that.  do take it apart in a safe environment. 

You mean like this? I was also chasing a noise in my rear. Turned out the collar (gland nut) was lose 

Sorry the link does not work..  (But glad you found the problem..)

 

5 hours ago, Daluvian said:

chasing a noise in my rear.

And did it smell? 😂

The shock inserts sometimes fit a little too short for the gland nut to snug them tightly in the strut. A spacer (large washer) is usually provided with the shocks to shim the shock so that it locks the shock firmly in the strut. If you have any movement in that rod, it’s either the gland nut isn’t locking the shock snugly in the strut, or you’ve got a blown shock (even if new.) IMO

I isolated the noise to two bolts holding the differential to the mustache. I'm slowly working my way through all the noise sources. Soon all that will be left is that buzzing from the electric fuel pump.