Odd looking bracket on my 280z, any ideas?

[Jaymanbikes]

I recently purchased a 77 280Z, while replacing all the bushing I noticed this very home made looking bracket attached to the car.  It is bolted through the diff support bracket that also holds the control arm bushings.  It consists of a main base and attached to it is a stack of several pieces of plate that come up right under the rear sway bar.  Any ideas what they may have been trying to do here?

[pamato]

The metal plates are referred to as a 'mass damper'. These are usually used as a last resort to fix noise/vibration problems that crop up late in the vehicle's development cycle. By attaching the mass damper to the offending piece, you change it's resonant frequency - the idea is to move the resonant frequency to one that the piece is not likely to see.

[NewZed]

It's a stock factory piece installed on all 280Z's from the factory.  They just made it ugly.  It's shown in the Rear Axle chapter, twice, but the illustrations are poor.  "Damper plate".

[TimZ]

The metal plates are referred to as a 'mass damper'. These are usually used as a last resort to fix noise/vibration problems that crop up late in the vehicle's development cycle. By attaching the mass damper to the offending piece, you change it's resonant frequency - the idea is to move the resonant frequency to one that the piece is not likely to see.

Hmmm... that sounds familiar.  Somebody smart must have said that... ;P

[dmoralesbello]

My "78 has the exact same setup from factory.

[Ken Smith]

My 75 has them also. Many have said you can just remove them and save some weight. I guess if you feel a difference you could just re-install them.