Sticky: 370Z Transmission Failures (6MT)

Jsolo

Mine had a nasty whine from about 1K miles (bought new). It was very annoying, especially at lower speeds in the lower gears with the radio off. Sounded similar to a super charger whine. Test drove a few others at the dealer and was concluded it is standard noise for these cars. While in motion, with the clutch pedal to the floor, varying engine rpm would vary the pitch. Still trans related as doing the same thing while standing still resulted in no whine. The sound was most prominent between 2-3K rpm (regardless of gear), and was still present at higher revs but was drowned out by engine noise.

This drove me nuts. A $40K infiniti should not be making such sounds, even if it is a 6mt. On advice of those here and on the G site, at ~7500 miles, I changed out the trans fluid to redline MT85 (3.xx qts). First test drive yielded no improvement. Subsequently though, the sound was greatly diminished. It's still there, but nowhere as annoying as it was. While I wish it was gone completely, I can tolerate it now.

For $60 in fluid (you need to get 4qts as it takes slightly more than 3), it was a cheap experiment. It's now about 3500 miles later and the noise hasn't gotten louder. It's about the same as it was after a few hundred miles following the fluid change. The initial test drive after fluid change was only ~5-10 miles, so my guess is it needed a few heat cycles and more miles to fully coat all of the trans internals.

The tapping/clicking noise sounds like your shifter isn't going through the gates smoothly. There is an adjustment/alignment procedure when reinstalling the trans/shifter. You say the whine/howl goes away with the clutch pressed in. While this is happening, what's going on with the engine revs? Is it falling back to idle, or is at the same engine rpm for the speed/gear you were in?

The slight lurch forward when engaging firsts suggests the clutch isn't fully disengaged. I remember test driving a G or Z that had after market clutch and other performance mods. Getting it into first was quite the challenge.

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G37S Sedan 6MT, Eibach swaybars, Invidia Exhaust, Weaker Clutch Pedal Spring

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