Possible HD CSC Failure or Transmission Failure
 

Hello everyone. I have a problem and I am looking for someone with personal experience to help me understand my problem and my solution options.

I was at a track day earlier this month and I started losing clutch pressure. So I came off the track and I checked my RJM pedal and noticed that the AFP adjustment Allen bolts were loose. I tightened those bolts and adjusted the friction point of the clutch rod and everything seemed okay so I went back out.

Next run; everything is okay in the pits, I get on track and drive about 2 corners and all clutch movement is gone again.

I had noticed over the past week or so that my friction point of the clutch engagement was moving around a bit but that is sort of “normal” at this point. But at the track day it become impossible to shift or enter any gears.

So I was able to get the car home. I was able to purchase and install a replacement master cylinder and now I have a similar, repeatable problem.


-The clutch system is fully bled, the pedal is heavy and I can feel it moving the clutch inside of the trans.
-clutch in
-Engine start.
-I can freely shift into any gear BUT the engagement point is down at the very bottom.
(I have adjusted to 0% AFP and the highest possible clutch engagement point on the master cylinder rod)
-once you let the clutch out fully, all clutch actuation is lost. While the engine is running, I cannot engage/disengage the clutch at all. I cannot enter any gear. The pedal feel changes and becomes lighter.
-engine off
-pedal feel returns after a few pumps to being quite heavy and I can hear the clutch moving again.


Now before you go saying the normal “your CSC is dead” please read my mod list:
-RJM Performance Rev3 Clutch Pedal Assembly
-RBF600 (brand new for the track day and brand new for this master cylinder replacement)
-Brand New Nissan OEM master cylinder
-ZSpeed HD CSC installed maybe 50,000 miles ago.
-Z1 6 puck clutch and pressure plate installed in the last year with less than 10k miles since install.
Nissan dealership installed the HD CSC 50,000 miles ago but I did all the other work.

I am thinking the HD CSC is dying but I cannot understand why this changes when the engine is running. Which is leading me to wonder if it is something else. I am concerned about there being another potential problem due to the behavior not matching the normal "dead CSC behavior" that we all know and love.

Any advice or opinions are welcome. Thanks!

I am basically considering replacing the Internal CSC with the CMAK Kit from ZSpeed or the Z1 CSC Delete kit. I am not sure which one is better but I know A LOT of people have the CMAK kit and I haven't heard of anyone running the Z1 kit.

From your description. The CSC is dying. Engine heat is making it worse.

ZSpeed is the best option.

I had lots of problems with the Z1 Elimination kit. I would frequently need to readjust it, it failed once too. I'd stick with Zspeed's clutch products.

This is not a slave issue, It would be a clutch or master issue, Slave will leak externally if bad.
Slave will not cause a intermittent pedal issue.

Clutch or master cylinder issue indeed. Honestly I would avoid the Z1 CSC elimination kit like the plague unless you enjoy readjusting it often. Even Joe would say get the CMAK kit asap. Lots of choices for a clutch and flywheel. Z Speed offers excellent clutch related products. Thanks again Joe for helping out the Z community you deserve a metal!

Listen to this man :iagree:

Hey everyone,

After speaking to Joe via email. He said it looks like the clutch itself has failed. The CSC has some marking on it as if it was struck by something. Also it looks like the throwout bearing is not perfectly aligned with the clutch, so it is unevenly pressing on the clutch causing premature wear.

The clutch that is installed is the Z1 Motorsports 6 Puck clutch. I installed it in December 2019/January 2020 and have driven about 2700 miles since the install. I did make a youtube video about the install so I will be showing that video to Z1 if the clutch is physically broken when I drop the trans later this week.

Needless to say I am massively disappointed. I need to drop the transmission, diagnose all of the failed components and open up my bank account. yay.

CMAK kit is guaranteed, I'm struggling with clutch choices though because I really don't want to drop the $1500 to buy full replacements plus the CMAK kit. But I'm not sure I would want to buy another Z1 clutch if this one has failed in 2700 miles.

Man I am sorry to hear that. I hope it works out for you.

Barring a bad install, this looks like yet another Z1 success story :shakes head:

Hello everyone,

I wanted to provide an update on this item.

When I dropped the transmission yesterday I found that 4 of the 9 pressure plate bolts had rattled loose. I reconfirmed that I did torque them to the proper 29 ft lbs originally but I did not apply any loctite. The CSC was also pretty shot but that is to be expected since it was not replaced when I did the clutch and flywheel back in December.

Z1 has informed me that they use red loctite on those bolts. I see that Zspeed recommends blue loctite. My understanding is that red is never supposed to come out after being applied so I did not decide to go with red.

I cleaned up the threads of the bolts and bolt holes for the pressure plate mounting bolts, applied loctite to all 9 bolts, and torqued them to spec.

I couldn't find any visible damage to the Clutch, Flywheel, or pressure plate. So it seems like the issues were coming from a loose pressure plate and a dying CSC because of the uneven surface it was pressing against.

The CMAK kit has been ordered and I am optimistic that everything will be okay. I will repost to this forum post if anything goes awry during the reinstallation or subsequent test drives.

Let this be a lesson to all of those folks out there. If you have clutch behavior that changes between engine on / engine off, maybe your pressure plate bolts are loose!

Final update:

I have reinstalled everything and she drives great again.

The CMAK kit was easy to install and the first drive was good. It seems that my problems have been solved.