Originally Posted by vin17

I've had the '14 Z Touring Sport MT for 1100 miles to date.

Here's what I've found:

Shifting at anything below 3K in 1st, 2nd, or 3rd gear will cause the clunking.

Upshifting in normal traffic at 1, 2, 5 and 6 works best for "normal" in city traffic motoring with minimal clunking.

The clunking noise is the synchro and LSD out of sync due to low revs in the lower gears. I'm not sure what the gear ratios are, but I suspect they're high in 1 2 and 3. Higher revs in the lower gears cures all. It's smooth and quiet around >3500 rpms While it's understandable that the Nissan Z engineers designed it as such - it's annoying in slower traffic.

(1.)BTW, I checked the differential oil factory fill level at the dealership this week, and it's clear and full with a consistency similar to thin vaseline.

I also had the service manager check with the Nissan "DTM" as I complained at 150 miles about the clunking and mentioned that this forum has multiple threads on the subject, and using different differential and MT fluids - specifically RED LINE. (2.)The service manager informed me that NISSAN DOES NOT approve of using RED LINE oils. Of course you might expect that, but this dealership allows customers using their own oils if approved by NISSAN.

I asked them to check if Mobil 1 synthetic LSD was approved.

I'll update this post when I get more info.