Hello all, I am making this post for a buddy of mine who owns a 2003 350z. A few months ago, he started having intermittent issues with the transmission where he would be locked out of all gears. We towed the vehicle home and threw a new clutch (Z1 Street performance) With a new OEM throw-out bearing. With the transmission off, we learned that the transmission was a CD009 (cdo#2 markings, think this year came with a CD001) and also found small pieces that look to have belonged to the clutch. We also found that the output shaft had a little play but were told by Z1 Labs that it was normal. The car was bought as a full drift build, so we expected just a clutch issue. After breaking in the new clutch and even drifting at an all-day event weeks ago, just last night, the car started to have the same symptoms reoccur. Only this time, the car doesn't want to go into gear only when fully stopped. Once you get the car rolling, you can row through the gears just fine. At a dead stop, everything is locked out. And also occasionally at a stop, while pressing in the clutch, the clutch chatter from the flywheel does not go away. We have also checked to ensure that the master and slave have pressure and are operating. The car could have a bad transmission mount, which I'm not sure if it could be a factor. I'm wondering if it could be something internally failing on the transmission, as I doubt a brand-new OEM throw-out bearing would be the issue, any ideas would help. Thankyou!

 

bump having the same issue have you figured it out?

 

Bump… Also having same issue replaced my master, slave and flushed my trans fluid to try and fix the issue… still trying to bleed it and have noticed that when I’m locked out, if I pump 10-15 times it goes into gear like butter no hesitation. The second I take my foot off the clutch and try to put into gear again complete lockout

please post results and fixes I’ll do the same if I get to the bottom of it lol

 

Did you ever figure out what the issue was? I’m having the same problem.

 

I recommend pulling back the dust boot on the slave cylinder rod and inspecting for clutch fluid leakage. If the slave cylinder seal has failed, it will start filling up the dust boot with fluid and not be immediately noticeable. The OEM parts are affordable, so for peace of mind, I would replace the slave cylinder and re-bleed the system following the FSM procedure. It's usually a good idea to do a bleed session, let the car sit overnight and do a second bleed session. This gives time for the fine bubbles to coalesce in the line and make it easier to flush out. This is typically only needed when also replacing the clutch master, but still something I would do whenever opening up the clutch hydraulics.

Other thoughts...
1) If your transmission is using the older stamped steel clutch fork, these are known to flex a bit. It's worth upgrading to the cast iron fork that was introduced on later year VQ35DEs. The upgrade kit is available from Z1 and CZP last I checked. It should include a new fork, new throw-out bearing carrier, and new (shorter) fork pivot ball. Best installed when replacing a clutch since the whole trans needs to come down.
2) You can try adjusting the master cylinder rod at the clevis fork (clutch pedal). Assuming it's still the OEM setup, check the plastic bushings. If those have cracked and fallen out, that will create slop in the pedal travel. There are upgraded heavy duty billet clevis forks that eliminate the use of plastic bushings. I highly recommend using one of these vs. the OEM setup.
3) Check all your lines + flare nuts for any signs of leakage.
4) Check your pedal bump stops and make sure they are present and in good shape. Also make sure they are properly adjusted for the pedal switches.

Good Luck!
-Icer