I just noticed it today while back in parking in my garage but there's a pretty loud clicking noise coming from underneath, possibly the back of my car anytime I ease off the breaks after switching gears from a full stop. In my case it was from reverse to drive and vice versa. I don't know if it's always done this or if my tranny is going out or what!

Is it constant or intermittent?

If it's intermittent...

Are you sure or could vehicle and road noise at speed perhaps be drowning out the noise?

Have you been able to duplicate the noise/make it happen?

If it's constant...

Does it change in speed or pitch with varying vehicle speed?

A coupe of other questions, how many miles are in the car? Maintenance record ok? How old/how many miles are on the clutch? What about the brakes? Have you been underneath the car at all to see if there's something caught up in the undercarriage?

If you can duplicate it try making a recording, uploading it to youtube and posting a link.

Welcome to NICO!

Is it a single click each time you switch from forward to reverse - or vice versa. If so, it a wearing U-joint in the drive line. Or it could be a loosened coupling in the drive line.

It's intermittent, i.e. whenever I'm on the brake and switching between gears. I am due for my 78k mile service, I'm about to hit 80k. Here are two videos I was able to capture:

This one is probably the clearest
[youtube]http://www.youtube.com/watch?v=-MOUmGRNTNw[/youtube]

And this one too just in case
[youtube]http://www.youtube.com/watch?v=8TuzM4kUY1c[/youtube]

Definitely not U-joints. Unless some of our other readers have encountered this, I say it's time to let the experts at the Nissan Dealer have a go at it.

I've watched the videos a few times and been searching through the FSM off and on today, letting things percolate hoping I'd have some "Eureka!" moment, but I've got nothing so far.

There was a TSB a while back for this issue on Zs, Gs, and believe it or not, Armadas (basically things with IRS and RWD).

If you can, try and put your ear closer to the wheels to see if its coming from there.

The TSB was for the half shaft actually deforming elastically (twisting), building up energy, and then slipping (again, elastically) going from fwd/rev, or even changing gears.
If you pull your half shafts away from your wheel bearing and see no grease between the 2, and striations on the 2 mating surfaces, that'll be your issue. Grease the 2 surfaces with the heaviest duty grease you can find (preferably with a crap ton of Molybdenum Disulfide), re-assemble, and see if it goes away.

You might actually want to get the grease ("Molykote M77") from Nissan. It is imperative that you use the correct grease to sustain the longevity of the repair. Also, do not over-torque the axle nut.

Found the TSB:
http://www.notre350z.com/forum/files/up ... kClack.pdf

note- Nissan calls the halfshafts (or axles) driveshafts. Driveshafts to them are called prop shafts.

And here's a video of a guy performing the TSB:
[youtube]http://www.youtube.com/watch?v=r9NsxI8XbLs[/youtube]

CHEERS!

^^^^he is definitely on the right track. I was going to say the axles.

Pop the rear axles out, clean the splines, grease and re-install. Did this about a year ago and fixed the issue