Part #: 200-586
New OEM Genuine Nissan rear differential locking pinion nut. This will fit on Datsun 240Z, 260Z, 280Z, and 280ZX with the R200 differential. The R200 came factory in some of the late Z cars and is also a popular upgrade for the older Z cars. The quickest way to tell if you have a R180 or a R200 is by looking at the cover bolt pattern. Take a look at our differential cover gaskets to see the difference in the R200 and R180 cover bolt pattern.