Today I installed the C5 spring in my C6 in hopes of having a better feeling clutch. I am not noticing any improvement, but pretty much the same as the original spring.

The C5 spring I order is smaller than the spring the car came with. Is the C5 spring smaller than the C6 spring? I want to make sure I put in the right one.

Thanks.

 

C5 spring is smaller, feel is slightly heavier, better feel is with no spring.

 

Put some motul 600 or other high temp brake fluid in. Change it regularly. Leave the spring in there!

 

The over all problem w/the clutch feel in the C6 is NOT b/c of the clutch spring or because of your fluid.

The problem is that the geometry of the cutch pedal and push rod mechanism are such that it provides a "cam like", or "over-center" action, similar to a compound bow, when you draw it. The point and benefit of the design is to make it easy to hold the pedal down (like when waiting at a stop light), for the Corvette's primary demograph. The draw back of the design is that the "over-center" spot also happens to occur at the same point in the pedal travel as where the clutch starts to engage. This makes for tricky clutch engagment, slipping, and launches, and makes the clutch feel more "ON/OFF" than it needs to or should.

The Pedal assist spring, only exacerbates the situation, b/c it pushes UP on the pedal during the top 1/2 of the pedal travel, and pushes DOWN on the pedal on the bottom half of the pedal travel. This design "amplifies" or exaggerates an already poor design IMO. BUT it does make it "easy" to hold the pedal to the floor. The C5 spring only does this, slightly less, than the C6 spring does, so you (the OP) are right; it is "pretty much the same as the opriginal spring".

Removing the spring completely is the most effective way to improve actuation, and restore a more linear pedal feel, for the least amoint of effort and money. The next "big" step in improving pedal feel or actuation would be to alter the pivot point location, for the junction of the pedal and pushrod, in such a way that you remove the "cam" or over-center geometry.

 

Thanks for the responses guys. Appreciate it.

When looking the responses about the C5 spring, I was expecting more of a stiffer pedal than what the original spring offered.

Just seems like a waste of money for the spring, but isnt everything we put on these cars a waste of money?

That's what the wife thinks

 

I spent most of my money on fine cars and beautiful women, the rest I wasted..............

 

The spring is $8. Get it if you want to try it but I think youre messing with fire there. I thought it was a good idea to take mine out, now Im having to replace my clutch at 9000 miles. $1600 down the hole. Well its an upgrade clutch and flywheel so I guess its not down the hole but I couldve waited more than 9000 miles haha.

 

Pissst. He already got it. And he already tried it. Didn't like it.

 

There was a bulletin from GM about why not to remove the spring, but I can't find it. My spring broke off a few months back, and the clutch felt a bit odd until I found the problem. I like the clutch better with the spring.

I got the most improvement by replacing clutch fluid til clear, and
also with my little gizmo to reduce clutch throw:

http://forums.corvetteforum.com/phot...00/ppuser/6747

As a note, when the clutch spring was replaced in November, they also replaced the clutch slave, and since then I don't need to flush the fluid.

 

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

 

...Which the "feel" that the engineers were apparently going for, sucks. Put a plain old coil spring on the clutch pedal that pulls it "up", lightly. Pedal feel improved (but still not completely fixed), and no issues w/the replenishing port function.

 

I believe, the C5 clutch return sping is GM Part No. 10376347.

After my clutch return assist spring broke, I drove for a couple weeks without it. I never had a problem using the clutch before the spring broke and I didn't feel it was any better without it. I put a C6 clutch spring back in.

 

UPDATE:

Proof of my lack of motivation to work on my own C6...After owning the C6 for over three years, I FINALLY climbed under the dash (actually, while I was installing HUD and had to pull the dash anyway) and studied the clutch pedal geometry.

The geometry of the pedal, push-rod, and pad pivot points is NOT the problem w/the C6 pedal "feel". The "poor feel" being the compound bow-like over center behavior.

Although the pivot point of the push rod/pedal arm does go "over center" some, it is not nearly enough to be the cause of the clutches feel. The push rod pivot point is about as far past the pedal's pivot point at full depression as it is, ahead of the pedals pivot point, at full release. Which is, not much. Maybe 25*?

So the behavior must be b/c of the diaphragm in the clutch itself. I can't see how it could be in the hydraulic system; that system is completely linear.

Has anyone installed an after market clutch in a C6 and recognized a significant improvement in clutch behavior (feel) over the pedal travel?

How about engagement? The C6's clutch engages very abruptly. Annoyingly so, IMO.

My recent purchase of a '92 C4 reconfirmed in my mind, what a proper GM clutch is supposed to feel and behave like; smooth, easy to modulate, and consistent. Nothing like what comes in the C6 at all. My recent test drive of an '05 CTS-V further confirmed this, and also proved that the C6's clutch feel isn't "because it's 400 hp"...as I had given some merit to that possibility.

Can any aftermarket clutch users chime in here?

 

Thank you sooo much.This is the first accurate answer I have had to my question of the clutch. A crappy design for a clutch if you ask me. I'm gonna fix mine asap.

 

yea I know what you mean, GM just put that spring there because they needed something to waste money on.

 

These genuis's who recommend removing the spring!
Thinking it FEELS better LOL! When it's designed to be there!
I had mine out for a couplke days on my Z-06 c-5. The pedal felt
like crap and didn't return all the way to the toip.

LEAVE THE CLUTCH SPRING ALONE! DON"T FOOL YOURSELVE,
Into thinking it's better! LOL!