I have 2007z with 54000 miles.My car lately fill very loose,for example when the car is in 4 gear and I press gas pedal and relise it you can tell ther is to much freeplay. It's making a loud '' boom-boom'' noise.Mabey it's drive shoft joints or rear differetial bushing?(I don't see any sign of leaking bushing in a S. frame) How can tell, because if my rear differential bushing are broken,I want to replace them with solid alluminum ones.

 

search "bushings" There are a ton of threads about this

 

Drive train problems are difficult to diagnose. Best to have a mechanic take a look. A careful inspect may show alignment of components that are not quite right.

 

Besides bushings what else can make this "Boom-Boom" noise? Do you guys know how much freeplay I am supposed to have in a differential? How far the axels supposed to move up and down? Mine move up and down less than half of a inch. Could that be the problem? I'm just trying educate myself befor i go to the Nissan Dealer.

 

Take a pic of the rear bushing and post it please.