c6 clutch issues
Thread Starter
Instructor
Joined: Dec 2004
Posts: 186
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From: la ca
c6 clutch issues
have 53,000 mi and lastnight after several tries my 1st gear grinds when I shift from neutral. Do i need a new clutch? I have been feeling it slip and ocassionally when downshifting from 3rd to 2nd with the pedal fully engaged it still grinds. New clutch time?
Retired & lovin' it!
Joined: Mar 2005
Posts: 4,475
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From: Jackson NJ
Sounds like it, but check the easy things first.....is the clutch fluid resevoir full? Is the clutch cylinder extending fully (you'll need a helper to check that)? Once you've ruled out the clutch cylinder or possibly a damaged throwout bearing, next stop is the clutch itself, but unless you've been real hard on it, you should be getting more than 53K miles of life.....
Le Mans Master
Joined: Feb 2008
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From: Lake Worth Beach, Florida
I lost my clutch at 55,000 miles in my C5. When it was removed it was determined that the springs had gone bad. I was able to get GM to pick up the cost of the parts, but the labor was still $1,600.00. If after you change/add clutch fluid and still have the problem, set up a claim with GM through their 800 number.
Thread Starter
Instructor
Joined: Dec 2004
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From: la ca
How do I check the clutch cylinder? I'm not to keen on that part of the car. I called a reputable mechanic in the Anaheim area (wink--wink) and was told that the clutch probably needed to be replaced, they also mentioned that if I was buying the LS7 clutch kit and only paying the labor that I should buy a new slave cylinder as well. The service person said that the slave cylinder was also a wear item and that it should be replaced while all that work is being done.....am I getting taken for a ride? I buy a lot of bling bling, car wash accessories, exhaust and I even have their lowering bolts (wink).
Can you submit a claim even after being out of warrranty?
Can you submit a claim even after being out of warrranty?
Race Director
Joined: Jun 2005
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From: Phila Suburbs 2023 C8 & 2013 650ix
Grinding going into gear doesn't indicate a worn clutch. It indicates that the clutch is not fully disengaging when the clutch pedal is depressed. There is a problem with the system that disengages the clutch not the clutch itself.
Le Mans Master
Joined: Dec 2004
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From: West coast CA
Maybe not. You describe two symptoms: slipping (clutch not fully engaged) AND grinding (clutch not fully released). Check the hydraulics.
Last edited by torquetube; Sep 4, 2008 at 04:39 PM.
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Thread Starter
Instructor
Joined: Dec 2004
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From: la ca
Well I tried swapping out the clutch fuid with dot4 Motul by method of a syringe and pumping the clutch pedal. Initially, I got good results and there was no grinding but it seems that when the fluid got mixed up a bit, the grinding came back. The clutch does not slip, but when I put it in 1st gear, it grinds in and then the speedo needle goes wacko and then I hit the gas and it does not slip. Clutch feels fine...I think. I tried several times with refilling the reservoir to flush out all the dirty fluid but it just kept coming back dirty. Should I have a mechanic bleed and inspect the hydraulic clutch system and see how that goes? How much should something like that cost? Any good socal shops that would do that for me?
Last edited by Sinister Evil; Sep 4, 2008 at 10:49 PM.
Team Owner
Joined: Mar 2008
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From: Southern Utah
Doing a true clutch bleeding, like one would do for the brakes, is almost impossible on the C6. If you will keep doing the fluid evacuation and refill in the reservoir, it will eventually stay nice and clear. It took me about a bottle and a half of DOT 4 to do this. I would empty the fluid and refill, drive for about a week, and then do it again. It probably took me about 8 times till the fluid remained clear.
Le Mans Master
Joined: Feb 2008
Posts: 5,636
Likes: 1,185
From: Lake Worth Beach, Florida
How do I check the clutch cylinder? I'm not to keen on that part of the car. I called a reputable mechanic in the Anaheim area (wink--wink) and was told that the clutch probably needed to be replaced, they also mentioned that if I was buying the LS7 clutch kit and only paying the labor that I should buy a new slave cylinder as well. The service person said that the slave cylinder was also a wear item and that it should be replaced while all that work is being done.....am I getting taken for a ride? I buy a lot of bling bling, car wash accessories, exhaust and I even have their lowering bolts (wink).
Can you submit a claim even after being out of warrranty?
Can you submit a claim even after being out of warrranty?
For the cost of the slave cylinder you don't want to cheap it out because the labor to replace that part is the same as the cost to replace the whole clutch assembly.
Last edited by Rocketmanwpb; Sep 7, 2008 at 12:55 AM.
Le Mans Master
Joined: Feb 2008
Posts: 5,636
Likes: 1,185
From: Lake Worth Beach, Florida
Well I tried swapping out the clutch fuid with dot4 Motul by method of a syringe and pumping the clutch pedal. Initially, I got good results and there was no grinding but it seems that when the fluid got mixed up a bit, the grinding came back. The clutch does not slip, but when I put it in 1st gear, it grinds in and then the speedo needle goes wacko and then I hit the gas and it does not slip. Clutch feels fine...I think. I tried several times with refilling the reservoir to flush out all the dirty fluid but it just kept coming back dirty. Should I have a mechanic bleed and inspect the hydraulic clutch system and see how that goes? How much should something like that cost? Any good socal shops that would do that for me?
One way you can test your clutch is to set the parking brake and place the car in 4th gear, then let the clutch out. If the motor stalls then the clutch is OK.
Team Owner
Joined: Mar 2008
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From: Southern Utah
If it isn't slipping but only grinding, then the clutch isn't being fully disengaged. And if doing the fluid made it better at first, then I suspect the clutch master cylinder as it had the new fluid for a while, then once it all mixed and some of the bad fluid came up to the MC, the problem came back. Master cylinder would be very inexpensive compared to the clutch. But if you have to do the clutch, replace all the parts including slave cyl, and get better, hi-po ones...as stated above, most of the cost is the labor.
Thread Starter
Instructor
Joined: Dec 2004
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From: la ca
From what I gather in the info, grinding of the gears is not indicative of a worn clutch. I went through about a bottle of dot4 clutch fluid and still could not get it to fully clear. The bucket I was dumping the old fluid into was still showing dirty fluid. I will continue to flush and drive the car until the fluid clears....I'm trying not to grind 1st gear as much as possible as I'm sure this can cause damage. I will try the 4th gear with the parking brake thing tonight to test the clutch out. I will keep everyone posted....you folks are the best!!!
Last edited by Sinister Evil; Sep 4, 2008 at 11:44 PM.
Melting Slicks
Joined: Aug 2008
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I'm certainly no expert but I suggest you KEEP AT IT! The fluid-changing regimen is a cheap way to eliminate one possibility! If you have gone through 2 or three bottles and see no real improvement in performance, at east you have eliminated that issue.
It made a major difference in my 05 with only 10,000 miles and I was still getting dirty fluid after the better part of one bottle.
It made a major difference in my 05 with only 10,000 miles and I was still getting dirty fluid after the better part of one bottle.
Team Owner
Joined: Mar 2008
Posts: 21,502
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From: Southern Utah
From what I gather in the info, grinding of the gears is not indicative of a worn clutch. I went through about a bottle of dot4 clutch fluid and still could not get it to fully clear. The bucket I was dumping the old fluid into was still showing dirty fluid. I will continue to flush and drive the car until the fluid clears....I'm trying not to grind 1st gear as much as possible as I'm sure this can cause damage. I will try the 4th gear with the parking brake thing tonight to test the clutch out. I will keep everyone posted....you folks are the best!!!
Like I said, my reservoir took almost two bottles of DOT4 to stay clear...and it was exactly one year from the day it was built. If your fluid is older or worse, it could take even more. After all, what you are doing is basically just a continuous diluting of the bad fluid until its almost all good fluid. And DOT4 is cheap...
Thread Starter
Instructor
Joined: Dec 2004
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From: la ca
i had thedealer inspect the clutch hydraulics and the entire system minus the slave cylinder which can't readily inspected. They basically said that the rubber seals appeared to be swollen and the fluid was contaminated with another liquid that was not clutch fuid. I have always used dot4 fluid so I don't understand that...but basically I was told I need to replace the entire clutch hydraulic system: Clutch Master Cylinder, slave cylinder and while i'm at it might as well replace the clutch and flywheel. They estimated the work at ~$2300 
because I got a discount..haha. I guess it's time to find a good So Cal mechanic and buy my parts at GMpartshouse unless anyone know where I might find these parts cheaper.
2006 C6 Z51
-LS7 Clutch and flywheel kit
-pilot bearing
-slave cylinder
-clutch master cylinder
because I got a discount..haha. I guess it's time to find a good So Cal mechanic and buy my parts at GMpartshouse unless anyone know where I might find these parts cheaper.2006 C6 Z51
-LS7 Clutch and flywheel kit
-pilot bearing
-slave cylinder
-clutch master cylinder
Thread Starter
Instructor
Joined: Dec 2004
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From: la ca
has anyone heard of replacing the entire clutch hydraulic system due to "contamination"?
The mechanic said the rubber seals were "swollen" due to the contamination. What the..........?
The mechanic said the rubber seals were "swollen" due to the contamination. What the..........?
Last edited by Sinister Evil; Sep 6, 2008 at 03:14 PM.
Team Owner
Joined: Mar 2008
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From: Southern Utah
I'm a bit skeptical of this....I don't know how they can tell that the seals are swollen without disassembly. I would continue changing the fluid, and as long as you are not doing damage by grinding, give it more time. Contamination could only be condensation of water, unless you are not sure that someone put something else in there. Good clean DOT4 will fix this also, but it takes time.