Clicking sound in rear

Could be lots of things but firstly I would check that his wheel nuts are done up correctly. Then I would check that his cv boots are in tact, then I would look at the discs to see if there may be a stone stuck also see if there are any stones stuck in the tyre similarly nails or sticky tape. Clicking usually means something is turning particularly does it speed up the faster you go.

 

It could be LSD chatter. Does it happen when turning or also when totally straight? If it only happens in corners at slow speeds then you need different gearbox oil or add friction modifiers, do a search within this forum on these terms, you will find plenty.

Be aware if the sound also happens going straight. A known issue with these cars is that the clip holding the internal reverse gear in place can snap if reverse is abused; which can eventually lead to the gear falling into the gearbox! This event will munch it.
I don't know however whether this condition pre-announces itself with any sounds. Does anyone know? And perhaps the condition of this part can be endoscopically checked?

 

I had this same exact issue with my 575 when I 1st purchased. I took it to Algar Ferrari where they were quite familiar with the issue. Apparently it is somewhat common on the 575. I just pulled the invoice from my file and following is a description of the repair:

Technician removed both rear axle shafts and applied loctite on axle shafts. Technician then installed 2 new axle nuts and torqued bolts and reassembled vehicle.

All I can say is it worked. I never had the clicking sound again.

 

Interesting. Thanks for sharing.

 

That repair sounds very plausible, I believe I had a BMW once that indeed made a 'tinging' sound when the load on the drivetrain changed direction. It was solved in a similar manner.

 

Makes sense to me. Had the exact same problem with my S2000, which apparently was common for the early cars.