I have installed a new Jim Wolf Tech JWT Clutch and Flywheel Combo Kit last year in my 2003 350z drift car. Put maybe 50 street miles and 3 drift practices on it. A couple weeks ago at drift practice my clutch pedal would not always return. The clutch was engaged and not slipping when the pedal wouldn’t return. Didn’t really happen when drifting as lifting the foot off clutch fast it would return. Then I heard a rattling noise when idling in neutral. Pressing the clutch in would stop the rattling.

Pulled the trans and throw Out bearing seems to spin fine smoothly by hand. The center section of the bearing looks like it is not centered. See pic. 11 o’clock position. Rest of clutch Components look great and in new condition.



Thoughts why pedal won’t return? Could that be related to the throw out bearing? Why is throughout bearing off centre?

thanks.

 

Overheated clutch fluid will cause the pedal to drop and not return.

 

Thinking a little more about this. I bought the car with a blown clutch. Put the JWT clutch in with light weight flywheel. Had issues getting clutch bled. Thought I had it right. But Always thought the friction point was a bit high. But I have not driven any other 350Z than this one so nothing to compare to. Clutch had good bite so did it worry about.

 

Make sure the clutch fork pivot ball is the right one. The 2003 model year trans had a longer pivot ball vs. later years. The OEM pivot ***** were prone to breaking under years of use/load, also the 2003 clutch forks were prone to flexing as they were stamped steel and not cast. There are upgraded replacements for all of these components. As for pedal return issues, more likely than not, the clutch fluid still has air bubbles in it. The picture you provided looks like the clutch fork has been upgraded/replaced with the heavier duty cast unit. Also, a good throw-out bearing should not spin/coast freely. If the bearing is packed with grease properly it should spin by hand with some resistance, but it shouldn't keep spinning/coast like a fidget spinner. If it exhibits this behavior, then the bearing is shot and should be replaced.
-Icer

 

Thanks Icer.

Throwout bearing doesn’t spin freely like a fidget spinner. It spins smoothly with resistance like you describe.

I will look at the rest of the parts at my shop tomorrow.

 

Here's some popular examples of clutch fork upgrade kits for '03 350zs.

CZP Kit

Z1 Kit

I highly recommend the chromoly pivot ball.
Good Luck!
-Icer

 

I have the Cast fork. I don't know what Ball I have.
I ordered the following parts from NAPA:
Master Cylinder (rebuild kits are 6-week order from Nissan dealer in Canada)
Slave Cylinder (both the master and slave look well used)
Koyo throw out bearing
Throw out bearing sleeve
New pivot ball

I asked for the pivot ball that goes with the cast fork and Napa guy was able to confirm that he has the right pivot ball

I didn't order from CZP or Z1 as I am in Canada and shipping can be a pain, especially with COVID. I should have parts Tuesday/Wednesday and I plan to go drifting on Thursday.

 

And thanks for the feedback everyone!

 

I recommend Honda's UREA grease for the throwout bearing sleeve and other parts of the clutch fork that see metal on metal contact (including the slave cylinder rod to fork). This stuff is great.
Amazon .
Also, make sure there's no play in the transmissions input shaft. If possible, also confirm the model of your transmission (white sticker on side of bell housing). I find it interesting that your 2003 already had a cast fork in it. It's possible someone before you upgraded the transmission.
-Icer

 

How was bleeding the clutch for you? I found it not as easy as the brakes. is the correct way to 1) remove fluid from clutch reservoir with syringe, replace with fresh fluid. 2) pump pedal, hold, open bleeder valve. 3) repeat the process until fluid in reservoir has seems clear.

Is this the method you used? (its the only method I know of)