Transmission rattles when in neutral (84 GTV6)

[Ryan.Murray@domain.elided]

I just noticed that my transmission (or that area back there) makes a
rumbling sound when I put the car in neutral (5 speed).  When I engage the
clutch the sound goes away and the car is relatively quiet (just the nice
purr of the engine).  Do you know what could be causing this and how to
remedy it.  Does this mean the clutch is loose, or going bad?
Thanks.

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