NizDan

I have a 2006 base redline 6MT. Fully stock, except NISMO exhaust. 37K on it.
Whenever I am cruising along at a leisurely pace, or doing normal highway speed, and then decide to punch it, even half heartedly, my RPMs will go from say, 2750 to 3500, then back down to 3000, then the acceleration will respond like I expect it to after this little RPM 'trick'. It notice it mostly in crusing gears 4th to 6th. It may happen in 3rd or lower, but I'm usually already cruising when It is most noticeable. There is always that spike up in RPM, then back down, then up again, all happens in a a second or less. It almost feels like clutch slippage, and in most cases. I wouldn't hesitate to say it is the clutch....but when I take off hard from a stop, it does not occur and there is no slippage. When I start on a hill, it does not do it. I have to be cruising at a leisurely pace, or be on the highway in cruising mode for it to happen. I'm not going to fully discount it being the clutch, but I did take it to Nissan and they took it for a drive, checked out airflow, had it on diagnostic, etc. They are not sure what it is yet either. If it was the clutch, I'm certain they would have told me...I think?
Any advice/comments much appreciated.

jray8

based on your symptoms my guess would be the clutch, give it the 6th gear test. start out around 20-25mph, shift from 2nd to 6th, then punch it, now obviously the rpm's will drop then rise accordingly, but you should be checking to see if you can "feel" the car accelerating. if the car starts to pull and you feel it along with the rpm's increasing, clutch should be fine, if the car just starts to judder/shake, and no noticeable increase in speed while the rpm's increase, then more than likely the clutch is worn. hope this helps, as it has worked for me several times, gl

NizDan

OK, will do and report result later. Though to this point everything is quite smooth and I get no shudder whatsoever. Thanks.

davidv

iTrader: (2)

Sounds like a perfect description of slipping clutch.

A slipping clutch will "slip" at low torque. Sixth gear at 50 MPH. Attempt to accelerate. RPM will increase but MPH will not. The spike in RPM occurs when the clutch plate catches the flywheel.

NizDan

I would have to wholheartedly agree that it is is likely a slipping clutch. But I am wondering why it doesnt slip all the time, such as when taking off in first, it grabs quite well actually. Why would it slip at low torque and not the higher take off torques? It just doesn't make sense to me.

OK, so let's assume I need a new clutch, should I replace the pressure plate also, or do I just need a to replace the disc, as I assume that is the worn item. However, since it is going to great pains just to replace the disc, might as well upgrade the clutch at that time, which seems to be the logic.

If I replace the plate and disc, does anyone have any recommendations on a decent middle of the road, not terribly expensive, but not OEM either, clutch kit. I don't want a race feel either, I love the car, but it is not a track car and never will be, its my daily driver and I want it to feel like that....and I don't want to replace it for a long time again.

Update:
took it to a performance shop and they test drove it...verified it is clutch. Its not severe yet and very driveable, but need to plan to replace soon.

I also understand the physics much better now as far as not slipping in lower gears as much. Makes perfect sense.

I am going stage 1. Maybe lighter flywheel too...maybe.

NizDan

Today is the day....
I picked up a new clearance priced Nismo r-tune clutch and pressure plate for virtually half price...from Nissan dealer of all places!
It is in the shop being replaced as I write this. I pick it up after work. YAY! No more slippage!

I decided to stay with DM flywheel for now as I like that it dampens vibrations and the performance for me from the stock Z is very good I feel anyways. The DM is in good enough shape to continue using I was told. I also didnt have time to research, buy and wait for a new flywheel. The clutch needed replacing NOW, as in today.

I do know that I will probably go with Nismo light flywheel (21.6 lbs) next time as it is a good balance between acceleration and vibration/noise reduction. I'll post one more after I get a chance to drive it, than I can report on the DM flywheel/ Nismo r-tune clutch combo.

NizDan

yee haw!
What a huge difference in action. The clutch now engages sooner on the uptake and grabs way faster than stock. Takes some getting used to that's for sure, but eventually you do. I actually like this clutch pedal action way better, it's better defined and gives you a much clearer 'picture' of how the revs are transferring, better more solid feel. Definitely stiffer, but not overstiff. Perfect really.
NO MORE SLIPPAGE!! DM flywheel was in very good shape. Hope somebody gets something from this thread.
Total cost
Nismo clutch plate, Nismo clutch disc ($533 CDN)
Nissan Shop labour + taxes ($566 CDN)
Total = $1100 CDN.
Cheap really!
<EOT>

Koobi4sho

now obviously id have to drive it to tell but i can almost gurrantee that its your clutch, i have an 04 Z bought it at 44,000 miles....ive had it for two and a half months plus the 2,300 miles it took me to drive from my hometown to oceanside CA....it now has 50,225 miles and my clutch just burned out, i had the SAME problems about a month back, like shifting at higher RPMS to get on the freeway or like you said just giving it a little gas here and there...for awhile i thought my TCS was messed up but that wasnt the case, it just kept getting worse and worse so now it sits until i can find a cheap enough place to install another one....so id be careful because your post sounds exactly the way my z was like before she blew....and i mean i dont know how the previous driver drove his z but i dont beat my z what so ever, theres no point unless you have the money to upgrade or pay the price of ****ing your car up....so yeah im almost positive its your clutch

cheshirecat79

iTrader: (9)

I'm glad your problem is fixed.

Did you buy the car used?

There's no reason for the clutch to be shot at 37k miles. If you're the only driver of th car I would look into getting your technique looked at to make sure you aren't overly feathering the clutch. It would be kind of silly to have to replace the clutch in another 35k miles.

jebz240

iTrader: (5)

Glad you got it fixed. JWT costs about $800ish installed and purchased. The biggest problem with factory or Nismo is they flywheel. The JWT flywheel has a friction plate that is replaceable and is cheap so you should never have to replace your flywheel.
my .02

jebz240

iTrader: (5)

All it takes to burn a clutch is a few dumps at High RPMS... i am on my third one at 60k due to learning how to launch at the drag strip

NizDan

Sorry for extremely late reply..
I bought the car at 36000, just out of basic warranty. I am the third owner. I did not burn the clutch, itr was one of the previous owners.

350z2k3

iTrader: (5)

I believe with r-tune parts there is absolutely no warranty...was this true in your case?