C6 Clutches

[eboch]

Hi;

I am considering a clutch replacement in my 2005 Z51. The stock clutch slips a bit under hard, full throttle acceleration ... nothing major, but I find it uncomfortably "untrustworthy". Otherwise, I have to say that the stock clutch drives beautifully, has great peddle feel.

Does anyone have any experience with the use of newer Z06 dual-disc clutches or any other aftermarket clutches in these cars?

Reading various threads on other forums, I see comments that the lighter aluminum flywheels used in some of the clutch kits are really noisy ... or can give the car a really rough idle .... any comments?

Also have seen comments about the intensely "grabby" feeling of some aftermarket clutch/discs, making them difficult to use on a daily commute ... any comments?

I am looking for something that has more holding power than the stock clutch, but still has decent driveability. faster reving aluminum flywheel is mildly interesting ... but not "necessary".

Thanks
eboch

 

[c4c5specialist]

HI there,
There are many variables with aftermarket clutches.
First, is installed height, which varies radiacally between the stock and aftermarket.
Second, is the actual friction material.
Third, is the quality of the installation and that all the fine points of installing these clutches be followed.
If you want the best stock unit, 06-08 ZO6 LS7 clutch would be your best bet.
It will require changing the flywheel, clutch plate, pressure plate, pilot bearing and the slave cylinder, but it will be just as great a feel as you have now, with a slight bit more pedal effort.
BUT, the feel and progressiveness will be there and it will be stone dead reliable.
Allthebest, c4c5

 

[eboch]

C4C5;

I am actually planning on using the Z06 clutch.... so we are thinking the same way.

I have investigated doing this myself ... it's a little more than I can handle because I don't have proper lifting equipment for the rear end that has to come out. So, a local performance garage is doing it. They told me that they have done these clutch upgrades on C6s and re-used the stock C6 flywheeel and slave .. only replacing the pilot bearing. They told me they had previously talked to GM and to the clutch OEM.

Are you indicating that this does not work?

Thanks
eboch

 

[c4c5specialist]

YOU CANNOT USE A ZO6 clutch with a flat flywheel, and have it perform correctly.
Slave cylinder YES, NOT the flywheel.
IF you do not use the stepped flywheel, you CANNOT use the correct pressure plate.
So in reality, you are only using the driven plate.
Do it ONCE, do it RIGHT, and dont forget the balancing pins that MUST be taken from the old flywheel and installed on the NEW flywheel in the EXACT same location.
Wouldnt GM use the flat flywheel if it worked correctly? THEY DONT!
Personally, I have never done it any other way except for clutch pressure plate, driven plate, flywheel and pilot bearing.
I do NOT reuse the slave, but I have used the standard slave part number that the car was originally equipped with.
Allthebest, c4c5

 

[eboch]

Thx for the info C4C5.

I am replacing both the plate and the clutch ... so I am [obviously] concerned that this works properly with the flywheel. I have asked the shop to look further into the flywheel compatibility.

Regards
eboch

 

[Warp 10]

YOU CANNOT USE A ZO6 clutch with a flat flywheel, and have it perform correctly.
Slave cylinder YES, NOT the flywheel.
IF you do not use the stepped flywheel, you CANNOT use the correct pressure plate.
So in reality, you are only using the driven plate.
Do it ONCE, do it RIGHT, and dont forget the balancing pins that MUST be taken from the old flywheel and installed on the NEW flywheel in the EXACT same location.
Wouldnt GM use the flat flywheel if it worked correctly? THEY DONT!
Personally, I have never done it any other way except for clutch pressure plate, driven plate, flywheel and pilot bearing.
I do NOT reuse the slave, but I have used the standard slave part number that the car was originally equipped with.
Allthebest, c4c5

I was there with my C5 Z and the dealer techs didn't know what they were doing. I ended up getting a custom balanced rotating assembly w/new balanced flywheel and presure plate. That was probably the most expensive clutch job ever done there.

Although I have no problems or slipage, I am thinking of getting a new clutch assembly for my C6 Z. Am I wasting my money?

 

[c4c5specialist]

HI there,
I wouldnt really waste the money on an aftermarket clutch, unless your doing constant drag strip launching.
Allthebest, c4c5

 

[eboch]

C4C5;

According to further research, my car ,being Z51-optioned, seems to be equipped with the stepped flywheel now and therefore can be fitted with the Z06 clutch. This was checked with GM using my VIN.

This seems odd to me. If a C6 fitted with a standard clutch needs a flat flywheel ...then why would mine be fitted with a stepped flywheel? would the stepped flywheel not be incompatible with this clutch?

Any comments?

eboch

 

[c4c5specialist]

Wow, I stand corrected.
Yes, the LS2 and the LS7 flywheels are the same.
See, you learn something new every day.
Sorry about the misinformation.
So yes, you can use it as long as there is no appreciable runout.
Allthebest, c4c5

 

[eboch]

C4C5;

Thanks for double checking this for me. Fell better about my choices now that I'm hearing the same config info from 2 [qualified] souces.

Thx
eboch

 

[eboch]

Got the Z06 clutch installation done. The installation was indeed found to be completely compatible with the C6 flywheel and the other clutch & driveline components... no issues at all, completely compatible (note my C6 has the Z51 option ... I'm not 100% sure that all C6s are able to use the Z06 clutch without other mods to the car).

The GM Z06 clutch does have a lot more grab to it and is not as "pedal-easy" as the stock C6 clutch .... albeit the stock clutch had 20K miles on it, so it was worn in.

For those of you who might consider this for your C6, I'd advise you drive someone's Z06 clutch first ... they are considerably different in feel & drive.

eboch

 

[eboch]

An update ... after break-in...

I put a few hundred km on the Z06 clutch now. I have to say its smoothed out considerably. It's still "grabby" but the pedal operation is smoother and lower-effort .... more like the stock C6 clutch pedal feel. this makes it a lot more "driveable".

eboch

 

[NORTY]

The Z06 clutch is a good unit. I thought the pedal effort was easier than a base (2007) C6. I think the Z51 (2007) is easiest of all. Almost "too easy."
The Z06 (2006) has 19,000 miles
The Base C6 (2007) has 30,000 miles
and the Z51 (2007) has 3,500 miles.

 

[Jimmyz]

I was told the C6 LS3 M6 vette's have the exact same clutch setup as the C6 Z06 does. Is this not true?