[Z06] Clutch problems???
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Instructor
Joined: Mar 2008
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From: Fenton MI
Clutch problems???
My 01 Z06 had a brand new stock clutch put in at 24k. I now have 32k, but I just added a cam, LTs, and cold air. Im making 420rwhp now, and I have noticed after a few days driving the new setup, that if I get on it hard for a few gears, the clutch seems to engage at/close to the floor rather than higher up as it did right before hammering through a few gears. I do not slip the clutch between gears more than normal. Is this clutch not holding? I dont feel, hear, smell any slip. Someone mentioned a FLUID issue? what do I need to check before spending 1500 on a new clutch? Thanks!
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Instructor
Joined: Mar 2008
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From: Fenton MI
answer
It only does after getting on it hard. Usually a 1st gear roll WOT to the top of 3rd will make it have this problem. I would not guess that its slipping, but the FEEL of where the clutch engages relative to the floor completely changes after the WOT.
Racer
Joined: Sep 2007
Posts: 382
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From: CT
see post 25 and 26 in this particular thread for fluid issues:
http://forums.corvetteforum.com/c5-g...tay-clean.html
search on 'ranger clutch' the same issues you describe are often resolved by fresh fluid, which can take several changes when flushed without bleeding....
http://forums.corvetteforum.com/c5-g...tay-clean.html
search on 'ranger clutch' the same issues you describe are often resolved by fresh fluid, which can take several changes when flushed without bleeding....
Race Director
Joined: Aug 2000
Posts: 10,649
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From: Central Florida
The LS6 clutch is fabulous at stock and near stock power levels. The question to resolve is whether your current torque level is too much for the clamping power of the clutch.
Only one way to find out. Start by completely cleaning up your clutch fluid.
I'd use DOT4 fluid and put at least 24 ounces of fresh fluid through the reservoir.
When the new LS6 clutch was installed at 24K miles, did the job include a new master cylinder and actuator/slave? If those elements were fresh 8K miles ago, then they should be salvageable via fresh fluid. If they are original and have been run for 32K with dirty clutch fluid, then you may be experiencing a leak in the internal seals that manifests itself under max power and repetitive strong shifts.
The way to verify which it is, is to clean up the fluid methodically until it stays clean after driving.
Ranger
Only one way to find out. Start by completely cleaning up your clutch fluid.
I'd use DOT4 fluid and put at least 24 ounces of fresh fluid through the reservoir.
When the new LS6 clutch was installed at 24K miles, did the job include a new master cylinder and actuator/slave? If those elements were fresh 8K miles ago, then they should be salvageable via fresh fluid. If they are original and have been run for 32K with dirty clutch fluid, then you may be experiencing a leak in the internal seals that manifests itself under max power and repetitive strong shifts.
The way to verify which it is, is to clean up the fluid methodically until it stays clean after driving.
Ranger
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Instructor
Joined: Mar 2008
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From: Fenton MI
more info
my clutch was replaced with a new stock clutch, but I doubt that the master/slave were replaced also. What I have noticed is that I dont have to shift to get this problem. I can be rolling in 3rd at 2000rpm and go WOT until 6500rpm (still in third) and then the same problem is there where the engagement is at the floor after only the single gear pull. The clutch is not slipping, I can hear my nitto drags about to free spin the entire time and the car is pulling hard! Then, after 10-20 seconds, the problem is gone and the engagment feel is back up at the top how it normally is. Now what?
Race Director
Joined: Aug 2000
Posts: 10,649
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From: Central Florida
Change in the engagement point under the conditions you describe reaffirms the need to follow the suggestions I made in post #6 above. If the symptoms continue after you make the clutch fluid pristinely clean, then swap to a new master cylinder and keep the clutch fluid clean.
If the symptoms continue, you need to go to more expensive part swaps. But I'd suggest taking it a step at a time. A lot of unnecessary clutch swaps get done.
Ranger
If the symptoms continue, you need to go to more expensive part swaps. But I'd suggest taking it a step at a time. A lot of unnecessary clutch swaps get done.
Ranger
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Thread Starter
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From: Fenton MI
good info
I did read the info from the last few post and it was very informative. I have been replacing the fluid in the reservoir a few times now, but I think Im going to pull the exhaust and bleed it also from below. I would like to replace the master first, before doing the clutch and slave. Do you really think that this power level can be handled by the stock clutch?
If I do need to replace, what is a good clutch to use? LS7 clutch and slave? thanks for all the advice
If I do need to replace, what is a good clutch to use? LS7 clutch and slave? thanks for all the advice
Race Director
Joined: Aug 2000
Posts: 10,649
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From: Central Florida
I did read the info from the last few post and it was very informative. I have been replacing the fluid in the reservoir a few times now, but I think Im going to pull the exhaust and bleed it also from below. I would like to replace the master first, before doing the clutch and slave. Do you really think that this power level can be handled by the stock clutch?
If I do need to replace, what is a good clutch to use? LS7 clutch and slave? thanks for all the advice
If I do need to replace, what is a good clutch to use? LS7 clutch and slave? thanks for all the advice
So the answer depends on those variables.
With that said, I'd avoid the LS7 clutch. Don't like mine at all. It has a tendency to glaze if the release is above 3600. I'm keeping it only because I'm a stock guy.
The only advice on replacement clutches that's worth listening to is from someone at your power-level whose driving style, tires, venues are very similar to yours. A good selection requires the same depth of due diligence you'd extend for an eye, brain or heart surgeon. No Kidding. Every thing your car does, depends on the clutch. That's why it's worth doing ongoing preventative maintenance on the fluid.
Ranger
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From: Fenton MI
update
Well so far I have removed the fluid from the reservoir, and refilled with new Prestone dot3/4 fluid. It is still getting dirty every time, but getter slightly better every time I change it.
To be quite honest, I launch the car at about23-2500 rpm every time, and let it fall on its face, just to protect my clutch. And when I shift, I let off the gas completely before shifting, again to protect my clutch mostly. The fluid changes do not seem to be helping yet, and this problem started about 200 miles ago.
To be quite honest, I launch the car at about23-2500 rpm every time, and let it fall on its face, just to protect my clutch. And when I shift, I let off the gas completely before shifting, again to protect my clutch mostly. The fluid changes do not seem to be helping yet, and this problem started about 200 miles ago.
Intermediate
Joined: Nov 2005
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From: Allentown PA
My Z06 does a similar thing the clutch is fine until the top of 3rd high rpms like 6500 the clutch fluid was dirty when I got it I changed it alot and got it clean but it still does the same thing. My clutch doesnt slip at all its just high rpms in 3rd gear that seem to get it engaging from the floor and not coming up much and once in awhile it wont go in 4th if I try and shift it really hard. I dont have a cam or lts but im pretty sure my master and slave are getting alittle old and tired with almost 97k on the clock. After a 3rd gear run if I throw it in neutral and pump the clutch quickly it will go back to normal position.
Racer
Joined: Dec 2006
Posts: 4,434
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From: Braselton GA
To increase holding power with the LS7, I wonder if GM went to a higher clamp plate and less aggressive material (more prone to glazing) to keep engagement manors streetable.
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Instructor
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From: Fenton MI
?
Should I just pull the exhaust and bleed the entire system the right way? Or just have the slave/master replaced? Replacing the fluid in the res does not seem to be helping. Im wondering if this may help before I have the clutch/slave replaced. I still dont think my clutch is slipping, because if it was it would have been completely shot by now.
Race Director
Joined: Aug 2000
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From: Central Florida
Is the clutch fluid DOT4 and have you changed it enough that, after driving the car and then inspecting the fluid, it is completely clear so that you can easily see the hole in the bottom of the reservoir?
Ranger
Ranger
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From: Fenton MI
to Ranger...
The fluid is not clear yet, so I know I did not yet follow your instruction completely. I am still changing the fluid in the res, but it is clear enough to easily see the hole at the bottom every time I do it now.
Le Mans Master
Joined: Aug 2006
Posts: 5,873
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From: Michigan
Just get a new Centerforce clutch
Almost the same price as stock and WAYY better
i beat mine and i used to have the clutch sticking issue not anymore !
take a look how wimpy it is compared to my Centerforce
Almost the same price as stock and WAYY better
i beat mine and i used to have the clutch sticking issue not anymore !
take a look how wimpy it is compared to my Centerforce
Race Director
Joined: Aug 2000
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From: Central Florida
Once the fluid stays clear after a drive, if the pedal woes continue, then next step is swapping out the master cylinder making certain you use the most up-to-date one for your VIN. If the accumulated clutch dust has already wasted one or more seals in your hydraulics, no amount of fresh fluid can restore a damaged seal. That why prevention is the key.
Ranger
Ranger
Melting Slicks
Joined: Apr 2007
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From: Northern VA
My Z06 does a similar thing the clutch is fine until the top of 3rd high rpms like 6500 the clutch fluid was dirty when I got it I changed it alot and got it clean but it still does the same thing. My clutch doesnt slip at all its just high rpms in 3rd gear that seem to get it engaging from the floor and not coming up much and once in awhile it wont go in 4th if I try and shift it really hard. I dont have a cam or lts but im pretty sure my master and slave are getting alittle old and tired with almost 97k on the clock. After a 3rd gear run if I throw it in neutral and pump the clutch quickly it will go back to normal position.
But i will have a sticky clutch pedal even after fresh fluid but its pretty minor.
Thread Starter
Instructor
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From: Fenton MI
still trying
I guess I will change the fluid a few more times to see if it helps. If not, I will pull the exhaust and bleed it the right way using dot4 fluid. Has anyone used dot5? If that does not work, I will then replace the master, and bleed it again. If it still has the same issue, I will have a shop install a new clutch/slave since I dont have a lift. I will let you guys know what fixes the issue. Thanks