Clutch Question higher gear pulls
Thread Starter
Safety Car
Joined: Nov 2005
Posts: 4,372
Likes: 936
From: Huntsville Alabama
Clutch Question higher gear pulls
Ok, my clutch does not slip, and feels good. no problems with a quick burst or anything.
BUT if i say kick it on the highway 4th gear run, and maybe some 5th... the clutch pedal gets squishy for the first 1/2 of the pedal or so.... but once you let out and push it once or twice its fine again??
the car is not slipping the clutch. holds good. so confused on what would casue this.???
clutch fluid is not dirty.
BUT if i say kick it on the highway 4th gear run, and maybe some 5th... the clutch pedal gets squishy for the first 1/2 of the pedal or so.... but once you let out and push it once or twice its fine again??
the car is not slipping the clutch. holds good. so confused on what would casue this.???
clutch fluid is not dirty.
Thread Starter
Safety Car
Joined: Nov 2005
Posts: 4,372
Likes: 936
From: Huntsville Alabama
Also a note, I do not have the clutch pedal spring installed, and I am not talking about slamming a gear and then it does this. I can have it in 4th and make a pull from say 3000-6500 and it pulls good. no slipping or reving. but when i go to push the clutch in at 6500 it works but the pressure is not at the top... shift to 5th nice and easy and roll into it and its a little worse after some 5th gear running. Car makes 438 to the wheels. has 50k on it, (just turned.)
Last edited by mittens; Oct 7, 2011 at 03:24 PM.
Race Director
Joined: Dec 2006
Posts: 12,385
Likes: 2,906
From: Fort Worth, Texas
The higher the gear, the more the strain on the clutch from a disadvantage mechanically and because of mechanics. It doesn't sound like your clutch is full on slipping, but it sounds to me like it is starting to slightly and the slippage creates heat which weaken the diaphragm springs and doesn't allow them to function properly fully disengaging the clutch. I'd recommend a replacement before it does any damage to the the tranny from grinding while trying to shift fast as it'll only get worse.
Race Director
Joined: Dec 2005
Posts: 11,885
Likes: 107
From: God's Country, ID
I recall a thread several years back regarding the early C6's (I had an 05 MN6).
The thread was in regards to the clutch going to the floor at times due to losing fluid pressure at high RPM's (or something of that nature). Do a search.
The thread was in regards to the clutch going to the floor at times due to losing fluid pressure at high RPM's (or something of that nature). Do a search.
Thread Starter
Safety Car
Joined: Nov 2005
Posts: 4,372
Likes: 936
From: Huntsville Alabama
also not sure how the clutch can KINDA slip on the higher gears... i would think if the clutch let go at all under power, its going ot let go the rest of the way... its takes more power to make the clutch slip in the first place then to take a already slipping clutch and spin it to red line.
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Le Mans Master
Joined: Oct 2006
Posts: 5,078
Likes: 19
From: Cumming, GA
I do numerous airstrip events and had issues like this at 500rwhp. Swapping out the stock LS7 clutch for a real aftermarket clutch eliminated that problem. No more clutch drama for me when running cars with 100+ more hp. 
Race Director
Joined: Dec 2006
Posts: 12,385
Likes: 2,906
From: Fort Worth, Texas
also not sure how the clutch can KINDA slip on the higher gears... i would think if the clutch let go at all under power, its going ot let go the rest of the way... its takes more power to make the clutch slip in the first place then to take a already slipping clutch and spin it to red line.
Le Mans Master
Joined: Jun 2009
Posts: 6,724
Likes: 652
My clutch has 60K miles on it and when I'm shifting into 5th at WOT ,the pedal is usually only half way up....just like my drag race launches. The combination of making full power ( low IAT, plus ram air effect), along with the aero drag, causes the pressure plate to heat up and give me the symptoms of a drag race launch. No doubt the clutch is starting to slip in this extreme speed environment creating heat and deforming the pressure plate fingers. I can get the same thing rev matching my downshifts and engine braking for corners during HPDE's 
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Ok, my clutch does not slip, and feels good. no problems with a quick burst or anything.
BUT if i say kick it on the highway 4th gear run, and maybe some 5th... the clutch pedal gets squishy for the first 1/2 of the pedal or so.... but once you let out and push it once or twice its fine again??
the car is not slipping the clutch. holds good. so confused on what would casue this.???
clutch fluid is not dirty.
BUT if i say kick it on the highway 4th gear run, and maybe some 5th... the clutch pedal gets squishy for the first 1/2 of the pedal or so.... but once you let out and push it once or twice its fine again??
the car is not slipping the clutch. holds good. so confused on what would casue this.???
clutch fluid is not dirty.
Nothing a couple of pumps of the pedal can't cure.
Thread Starter
Safety Car
Joined: Nov 2005
Posts: 4,372
Likes: 936
From: Huntsville Alabama
Yea mine will still chirp 2nd and 3rd... And it goes away after you pump the pedal once.. Just wondered what it was... I understand it more strain and stuff I know how the whole clutch work been there a few times replacing on my trans am... Just still think if it slips at all the power would spin up to red line not still hold like normal... But who knows I have been wrong before.
