niznos

iTrader: (2)

Looking for some input on a clutch problem. I just had a ZSpeed Stage 1 clutch set ( https://www.zspeedperformance.com/ZS...ZSPSTG1-DE.htm ) installed on my 04 touring with 68XXX miles by an acquaintance who is a mechanic at a local BMW dealer with 10 years experience, and prior experience in successful installs of clutches on 350z's. The problem is the clutch is not fully disengaging. With the clutch master cylinder rod adjusted all the way into the firewall, no threads showing, and the pedal pinned hard to the floor, I can get into 1st and reverse with significant effort. While in motion, gears can be selected only when the pedal is pinned hard, and 3rd and 5th will try to grind if not rev matched.

To answer some questions everyone will probably ask:
1. The fluid was flushed and bled since the problem started, even though the hydraulic system was never opened for the clutch install. The pedal is consistent, suggesting no air was left in there.
2. The master and slave are both less than 5000 miles old and show no issues visually or in their function.
3. The clutch hose was replaced with an stainless steel braided line when I did the master and slave. The heat sleeve from the stock hose was put back on this SS line.
4. I deleted the clutch damper orifice and there's just a union there now.
5. I had the RJM pedal prior to this issue, but I removed it and put in a stock pedal back in to diagnose this. That stock pedal was also less than 5000 miles old.
6. The clutch set was installed with a throw-out bearing, bearing sleeve, pilot bushing, clutch fork, and pivot ball, all new.
7. The factory dual mass flywheel was not replaced. It showed minimal wear so it was roughed up in place (not actually machined/resurfaced) and reused.

We are at a loss here. We tried to make a longer (+5 mm) slave push rod just to test it and it made no difference. It simply displaced fluid volume up the line into the reservoir, ultimately giving us the same slave travel distance. The recommended break in period for clutches is 500 miles. It has been about 100 and there's no felt difference and I'm not keen on grinding gears off to save from doing a clutch a second time.

The only conclusion we can draw is that there are problems with the variances in the hard parts like height of bearing/sleeve, angle of fork, height of pivot ball, friction disk thickness, pressure plate spring height and/or leverage angle. It is worth mentioning a couple of things about the clutch set from ZSpeed. The description stated the disk was "upgraded" to 250 mm diameter from 240 stock. This seems far fetched, but could the slight wear pattern of 240 mm on the flywheel, cause the extra 10 mm of the new disk diameter to hit unused and raised parts of the flywheel and hang on it? [Edit: I just did more research and the stock is 250 mm. I don't know the reason behind their 240 mm claim.]

I did pay for this service, and the mechanic feels at least partially responsible for the issue, so we can pull it down one more time and try to get it right, but I'm sure he's not going to do it anymore after the second time, so we have to have a plan that's going to work.

I'm thinking that I should get an OEM spec'd clutch set installed and reinstall the old fork, and pivot. Inspect and measure the old throw out bearing and carrier sleeve's total height and even possibly reuse the old bearing. At 68k miles, the old one was in good shape, but I'm iffy on this one. I'm considering it because this is not a daily driver and I'm averaging 2500 miles a year, at this rate, the bearing won't see 100k any time soon and might be ok.

Anyone with similar experience, or that's used this particular clutch kit especially, please chime in.

iideadeyeii

iTrader: (6)

I've had this happen on a jeep wrangler. The pressure plate has diaphragm springs on the edge(usually like 3 of them) One ended up being on the wrong side and caused the clutch to not fully disengage. I tried a longer rod and the master cylinder/slave/line were new

guitman32

iTrader: (15)

Are you sure it isnt over-stroking? What happens when you get it in first, and slowly release the pedal? Have you made sure the pushrod in the master cyl is fully released when the pedal is released? It definitely sounds like it isnt, which can cause pressure to build up (as called out in the RJM manual). This may also be contributing to the fluid rise in the reservoir, which shouldnt be happening. You should be able to do more diagnosis to determine exactly what is going on. It is either never fully disengaging (the car would move in 1st with the clutch in), or it is over-engaging.

Did you use a new OEM Nissan master and slave cylinder? Ive seen them go in very short order with the off brands and reman.

When I replaced my trans last year (new out of box CD00A- which comes complete with everything installed, lubed up and ready to drop), I replaced my JWT clutch and pressure plate with a new Z1 kit (same as the JWT on visual)...all variables equal my system would overstroke and re-engage with the pedal all the way in, causing the gears to lockout like you are describing. Rather than DIY a pedal stop to limit stroke I opted for the RJM pedal, which has the stopper built in and really improved pedal feel (almost unnaturally light, but still an improvement). Unlike your situation I didnt guess on the fork/pivot ball bc it all came assembled with the new transmisison...so the only variable could be clearances with the Z1 clutch and or pressure plate.

Otherwise you may have it mixed up with the pivot ball and shift fork.

niznos

iTrader: (2)

It's not overstroke because after the install, when I reinstalled the stock pedal, I installed it at the mid-point of the master push rod's threads. When used at this point, it would not get into gear at all. I then adjusted it all the way into the master, and got enough stroke to get it into gear, barely. The rest of the engagement feels good actually, except for the low-ness of it.

The rise in fluid isn't happening from normal operation of the master/slave. I said when we tried the longer slave rod it took up the extra length by displacing the fluid back up into the reservoir. If that doesn't make sense, then recall how when you replace brake pads, you push the caliper piston in and the fluid moves up the system back to the reservoir. When we put in the longer slave rod, it pushed the slave cylinder back in its housing, and thus fluid back in the system. In the end, the slave stroke length is dictated by the stroke of the master operating causing the actual travel distance of the clutch fork to be unchanged, the same way that after you push a brake piston back in, your brake pedal travel is the same. So the slave cylinder was moving the same distance, but just further in it's housing.

The master and slave are both non-OEM, but remember: they worked normally before the clutch set was installed. There's no reason for them to fail suddenly without showing any leaks or deformations and still operate with good pedal consistency.

When we pull the transmission back out, I'm putting the old fork and ball back in on the chance that there's a manufacturing defect or variance on them. Like the master and slave, they worked fine before all this, I just had the new parts so they were just all tossed in there.

I'm not fully understanding how an overstroke could cause it to re-engage, but I will test it out. Since I've tried it at mid-way and all-the-way in the master, I will try to set it at all-the-way out, and at around 3/4 out and see if there's a chance that is happening. But should I even try this since the engagement feels fine right now, but just too low? Seems like if it's re-engaging from an overstroke, it would not engage as well as it is currently.

I will gladly paypal you the cost of a case of beer of your choosing if this is all I need to do. It sure beats paying for a clutch job twice.

Thanks for the input. I will update once I have some time to play with it.

niznos

iTrader: (2)

I'm fully prepared to accept that the ZSpeed clutch kit was faulty in some way. With my luck, it wouldn't be very surprising. I've ordered an Exedy OEM kit for redoing it all. Unless we discover there's something glaringly wrong with the 1st install, we're just going to put the Exedy OEM set, old fork, ball, and bearing sleeve back in to avoid the possibility it not working again.

guitman32

iTrader: (15)

The interesting thing about adjusting our clutch system is that there is only really one position for the master cylinder pushrod, and that is to ensure the piston is full disengaged with the pedal in the uppermost (released) position without actually slamming into the housing when you release the pedal.

If you elongate the rod to the point where the piston no longer sits in its fully relaxed position with the pedal released, you are actually not helping your travel at all. Beyond this point, you arent getting any "extra" stroke, since you are taking away the overall travel of the piston in the cylinder. There is a small amount of slack you can play with, but it is very small. Any you may actually be causing pressure build in your system since the piston is not retracting past the point where it can relieve the residual pressure from the last pump via a port in the master cyl. If you ride like this for too long you can obv destroy your clutch.

Not saying your fork and pivot ball are the correct version, but it still sounds like it isnt adjusted properly. No need my friend, just hope your get your system figured out. Let us know what you find.

ZSpeedPerformance

iTrader: (71)

Have you tried calling us? The clutch should have no issues releasing correctly and I can pretty much guarantee the clutch itself is not the issue.
Please give me a call and we can go over this and get you squared away. 937-506-7224

Extended the slave rod is not helping you in any way, It has the same stroke no matter where it starts at. Doing this will do more harm than good.

niznos

iTrader: (2)

First off, let me apologize to Joe and ZSpeed. In hindsight and in rereading my OP, I realized it looked like I publicly called out his parts for being bad, without even calling him and giving him a chance to remedy the issue. It was not my intention to come off this way, and he should have been my first call.

I did call Joe at ZSpeed, and he was one of the most upstanding business people I've ever met. He went above and beyond what could normally be expected, and offered a lot of advice and insight about my issue that only someone with decades of experience with Nissans and Z's could offer. He was an all around nice guy, and I would not hesitate to buy from Joe in the future.

The actual problem on my car is not fixed yet, but I will update when possible.

Thanks again, Joe.

niznos

iTrader: (2)

I got an OEM spec Exedy kit, P/N NSK1000 installed and the car seems to be good now. I'm waiting on the break in period and probably some slight clutch pedal adjustment during and after that time frame, but I think I'm good here. Thanks for all the help and advice.

ZSpeedPerformance

iTrader: (71)

Glad it is working correctly now,

Just to be clear, The kit your brother had purchased on clearance from us 5-6 years ago you were trying to use was NOT the ZSpeed clutch you linked to in the original post, It was a stage 3 kit from a different manufacturer which we no longer carry and have not carried in at least 5 years.
These kits needed a perfectly flat flywheel and would need the pedal adjusted up (which he was told IIRC) or they could have an issue with proper clean release, since you were using your original used flywheel this may have been the reason it did not release cleanly.

Hopefully he gets good use out of the replacement ZSpeed kit we sent.