jptonks

Hello all,

My 2008 MN6 convertible, with 1200 miles on it, comes out of winter storage tommorrow. Last year, when I put it away, I thought that the clutch effort had become too soft, almost no resistance at all. With only 1200 miles on the car, I could not understand how this could have occurred from May 2008 (when new) until October 2008.

Has anyone else felt as if their 2008 C6 clutch effort was too soft? Is it my imagination or could a clutch pedal get softer as the car gets broken in?

I am fortunate to have a first-class Corvette mechanic in my area and I will bring the car to him very soon. However, his approach will be very much "the factory solution" and I know that forum members may have a different perspective on this.

I have never yet had the engine over 5000 rpm and I have never had the clutch pedal stick to the floor. If I remove the return spring in the pedal will I increase the pressure a little? If I go to a C5 spring , will the pressure be a little more as well? I am not trying to make the clutch stiff, just a little less like butter.

Any help would be appreciated. The car is street driven only and it is not a daily driver.

John T.

Craigster05

Yes, many feel the C6 clutch is to soft, you are not alone. The C5 spring does give a little more feel of engagement and effort, removal of the spring altogether gives you even more. It's a free mod....just take it off and see how you like it. There are plenty of us running without is for a long time, you do not have to worry about any ill effects. If yo udont like it, put the spring back.

Here's the procedure for you C5 Spring Swap

07MontRedcp

Service Information Chevrolet Corvette | Corvette (VIN Y) Service Manual | Document ID: 2099794
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#PIP3821B: Removal Of The Clutch Over Center Spring - keywords cylinder hydraulic master pedal - (Apr 15, 2008)


Subject: Removal of the Clutch Over Center Spring


Models: 1997-2004 Chevrolet C5 Corvette

2005-2008 Chevrolet C6 Corvette

Equipped with a Manual Transmission




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This PI was superseded to update model years and tac notes. Please discard PIP3821A.


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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
It appears that some Corvette owners are removing or disconnecting the clutch over center spring on their vehicles.

This is not a recommended practice and customers should be advised of the implications of such an action.

Recommendation/Instructions:
The clutch master cylinder has a compensation port that is positioned within 1 MM of the top of the stroke. The compensation port allows internal pressure in the clutch hydraulic system to be exhausted into the master cylinder and also provides for system refill as the clutch disc wears.

One purpose of the over center spring is to return the clutch pedal to the very top of the stroke to expose the compensation port. The second purpose of the spring is to provide for the designed clutch pedal feel.

Removing or disconnecting the spring may allow the clutch pedal to hang in an at rest position with the piston short of the compensation port. If the internal pressure is not exhausted the CSC may get stroked too far and a clutch hydraulic system failure may result. The C5 clutch hydraulic systems were built by AP. The C6 systems were manufactured by FTE. Also, the pedal must be in the full up position, with the compensation port exposed, to bleed properly.

Anytime a dealer gets a hydraulic system complaint, the tech should inspect to insure that the spring is in place and properly connected. Related customer complaints might include poor shift performance, improper clutch release or transmission synchronizer damage.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© 2009 General Motors Corporation. All rights reserved.

BJK

Craigster05

I'm sure you meant well, but your response will not help the OP who is asking about experiences on something he wanted to try to improve the enjoyment of his vehicle.

We all know that GM does not endorse modifying your Corvette in anyway (unless it is a GM accessory installed by a certified GM dealer), or racing your Corvette etc, etc, etc, yet 99% of the people that own them do.

It is our common experiences that we can pass along that not only help each other enjoy our Corvettes more, but allow them to operate better, more efficiently and more enjoyably in our particular environments and driving styles than the factory may have thought of to test in or provide for. For example, if we all lived and breathed by bulletins, you couldn't charge your cell phone in your Corvette:

Electrical & Lights: ELECTRICAL SYSTEM
Service Bulletin Number: 3134
NHTSA Number: 10017696
Model Years Affected: 2005
Date of Bulletin: 11/2005

Bulletin Summary: VARIOUS ELECTRICAL PROBLEMS WITH A CELL PHONE CHARGER PLUGGED IN.

That's just one example....extreme, maybe...but that's why members come to the technical forum...for help...not warnings....especially if there is no concrete or first hand information to back up that warning.

Since the OP asked for real world experiences, I can point him to over 25 Vette owners I know of comprising a few hundred thousand miles total, mostly raced and abused as well as daily drivers who have either removed their spring or used a C5 spring....not one has ever had a problem related to the removal or changing of the clutch spring. A forum search looking for a posted problem related to the bulletin will also turn up nothing. If you know of someone who did have a problem, please let us know so we can learn from what actually happened.

Here are more posts showing the same positive information:

http://forums.corvetteforum.com/c6-t...ifference.html

mike glenville

the clutch slips without the clutch return spring

07MontRedcp

I disagree. If you read thru the TSB, you will notice that they give the reason for using a clutch spring and the problems that can result without it.

BJK

deanm11

I don't run the spring in my '08 and much prefer the feel. Only about 2800miles, but absolutely no indication of any ill effect. Again, don't think we've heard of any reports of problems with running no spring, no matter what the bulletin says.

07MontRedcp

I just posted one by GM so I don't think that's an accurate statement, but that's not why I posted. I posted as general info for the OP as he stated that ANY help would be appreciated. He can choose to accept, ignore, or reply as it is HIS thread.

BJK

deanm11

Agreed, the poster should have all the info and make his own choice. I would be very interested to hear of a documented case of a problem as indicated in the bulletin among our crowd -- that would be further information for the original poster and all of us, if there was such a case.

Walt White Coupe

I ran my 05 from 22,000 to 32,000 miles odometer (10,000 miles) without the spring after it broke and fell out with no problems. If the spring in my 09 spring breaks, I'd replace it after seeing the TSB.

Joe_G

Heh...not true.

I am probably the hardest guy on my stock clutch on this board, with 301 5000 to 6200 rpm launches on my clutch with reliable 1.5 - 1.6 60 foots.

With no spring.

The car is my daily driver and has 34k+ on the factory clutch.

Based on my years of experience I'd say it's safe to take the spring out.

deanm11

I will add another point. Besides having a soft stock feel, I felt the spring gave a bit of a non-natural, non-linear feel as well. These cars seem to be tricky to take off smoothly (talking just gently leaving the stop light) and removing the spring gave me an easier time of it and more feedback.