peterskunk

C5 Clutch issues

After a speed shift I noted that my clutch slipped and the clutch pedal feels rare (like not returning completely). I got my vette un-molested so I think it has the factory clutch in there. I want to replace it with an upgraded (500-600hp) unit but in a budget.

For the knowledgeable guys in the forum need you advise here:

Flywheel steel or aluminum? Weigh? How many tooth my flywheel have?

clutch slave, wich one?

What kind of clutch kit I should buy? Single? Dual? Etc…

Any preferred brand?

thanks

pewter99

just get the LS7 clutch kit.......Gene at Cultrag usually has a deal on them on his website or you can call him....

direct swap....had one in my blown C5 and it worked flawlessly

Georgies

Mantic 9000 and be done with it.

neutron82

what is your budget?... mcleod rst and reuse your flywheel would be a good choice, you can upgrade to a billet steel flywheel if you want to spend more... the mantic is nice but probably more clutch than you need and pricey... check out act too, they make good clutches... skip the ls7 in my opinion, it will hold more power but is prone to the same pedal issues as the stock c5 clutch... for the slave and clutch master cylinder oem gm is fine

pewter99

interesting you mentioned the pedal issues, my 99 never had issues, my wifes 02 had issues until we went to the LS7 setup.....I may be wrong but I thought the pedal issues were 2001 and up...no? its been a while so help me out here.


hey OP, what are your plans for the car going forward? that may help with some more suggestions

peterskunk

So far I have installed a full exhaust system, 90mm throttle, msd wires, next upgrades will be nitrous kit and hp tunner tune. That’s why im thinking on a 500hp/tq minimum clutch kit.

thanks

sstonebreaker

If you drive the car daily, then the LS7 kit is the way to go in my opinion. It's not expensive, around $500, and while the kevlar type clutches will hold more ultimate torque, the OEM friction material is a lot more tolerant of overheating (think stop-n-go traffic) than kevlar clutches. If you overheat a kevlar clutch, it's toast; but an organic clutch like the ls7 will recover after it cools down.

Downside is the ls7 clutch and flywheel are heavy and will cost you a tenth or two in the quarter. If that's more important to you than longevity, then look into a lighter aftermarket clutch. But if you mainly daily drive the car, I think the advantages outweigh the disadvantages of the ls7 clutch.

bigmackloud

I went with the Monster Stage 2 single disc with lightweight flywheel. Granted I went a year and half w/o driving the car while I was rebuilding the engine, but the new clutch drives pretty much just like the stock unit. Not grabby, reasonable pedal weight.

If you have a bit more money, the Monster LT1S is a reasonably priced option for a twin disc which will hold even more power.

With any of them, make sure you get an installation kit, which will include the pilot bearing and a new slave cylinder. And definitely spend the extra $50 and get a remote bleeder for the slave cylinder (Tick Performance). Makes bleeding the slave and changing the clutch fluid a breeze.

NSFW

Does Monster's installation kit come with an OEM slave cylinder, or do they make their own?

bigmackloud

It is a GM slave cylinder. I bought my kit through Tick Performance.

NSFW

Dang. I keep hoping to discover an alternative. Thanks though!

neutron82

I've never used one but these sure do look nice, http://tiltonracing.com/product/6000...ease-bearings/

neutron82

I wasn't aware of specific years, as far as I know many manual c5's and c6's (except for the zr1) have pedal/shifting issues... of course a lot of it may have to do with how the car is driven and/or the driver... nearly every one I have seen that has added significant power has had problems shifting (my car included) and the only real way to get rid of it was a quality aftermarket clutch... I have had friends use the ls7 trying to be cheap and ended up in the same boat as they were in before... it will handle the power fine without slipping but the problem is when you start trying to race it and shift fast... personally I think the self centering pressure plate is the root of all the problems but I could be wrong and I'm not sure if anyone has a definite answer on that... if you are just daily driving on it or making a single gear sprint then sure it will probably be fine but I will never recommend it for someone who intends to race the car or drive/shift aggressively, and it sounds like the op is the latter... in my opinion, for just a few hundred bucks more it makes more sense to go with a better quality clutch

Spaceme1117

When I changed my clutch, I purchased the following from Tick Performance:

1. LS7 clutch and flywheel.
2. Tick Master Cylinder
3. New GM Slave Cylinder and shim kit
4. New pilot bearing.

NSFW

I suspect that's what's in Katech's C6 clutch slave package, and I think they had a C5 version available at one point:
http://store.katechengines.com/heavy...-kit-p337.aspx

If you notice the price you'll see why I'm still looking for an alternative.

Georgies

Thats alot of money...so are the Tilon ones... i guess thats what track (road racing) guys use...?

mike venth

Here is an article and information that I used on my 01 coupe/stick...I,m thinking which ever clutch package u use would be a good time to do these little extra...

CLEANING AND REPLACING CLUTCH FLUID-INCREASING AIR FLOW
However, what is stated here will help extend the life of the clutch by keeping the clutch cooler and the fluid cleaner for much longer than any other method. This is primarily meant for those of us with stock clutches but will apply to all the aftermarket clutches as well. We have heard of many people that have put clutches in their vehicle when it may not have been necessary or many feel it is a mandatory upgrade with more power.

On our shop car we have a heads and cam C6 z06 with 585RWHP and 535RWTQ and 82K miles STOCK clutch from new and the car is driven like it is stolen, daily. The car has some drag racing time on it at the track but it is mostly thrashed on the street and road coursed as much as time and the budget allow. We have NEVER had the pedal stick to the floor and it takes about 5K miles for the fluid to change color let alone turn dark.

Drag racing does play havoc on a clutch but hopefully this will get those that are apprehensive out there to beat the tar out of their cars like they should be, it’s good for them!! It has been our experience that the 2 worst GM V8 vehicles out there for having issues with clutches are the GTO and the F-bodies. I would like to point out one thing that they have in common: They do not have an "exhaust" for clutch debris and heat. The back of the bell housing does not have vents like the Corvette and especially the C6. The 2 C6 vents are about 2" by 3/4" just beneath the clutch and in the back of the bell housing whereas the C5 was about 1/3 the size. The late model Camaro has a large vent roughly equivalent to the C6 size.

I mention all of this as an important backdrop that we will come back to shortly and I will try to tie it all together.

Even though this is a LONG write up IN SHORT it will only help even if you aren't have any issues.

I tried to illustrate with my kindergarten drawing ability Check out the clutch airflow pic at the bottom.

-Bleed the clutch line
For many of us are familiar with Ranger's articles about using a turkey baster to draw out dirty fluid and then replenish with clean the fluid.

This helps, however it is not the solution for the larger issue, you will still continue to get filth in the clutch and reservoir.

Please understand I am extremely grateful for his contributions to the corvette community. Ranger sent the fluid to a lab to analyze what the dark substance was in the fluid and established that it was clutch material. Without this important piece of info we would have much less knowledge about this system. THANK YOU RANGER!!

As you USE the clutch you consume it and where does the debris go? As the clutch material is flung around within the bell housing the material gets past a seal into the slave cylinder and then the hydraulic system the fluid is contaminated and begins to darken. If allowed to worsen you eventually will have a sticking pedal and lose hydraulics. In most cases not permanent but often at the most inopportune times. It is best to address this as early as possible so you do not have permanent issues with the stock slave.

We are not sure but it seems likely that damage may be caused to the slave cylinder by the clutch particles embedding between the bore and piston of the slave. Catch it before its too late. Naturally a clutch should give off the most debris upon break-in.

The factory system moves a very small amount of fluid in a line from the reservoir to the slave, fore and aft. Naturally the most contaminants would be at the point of entry into the system, not just the reservoir two feet away. Bleeding the system like a brake or any other hydraulic system until the fluid is clear would rejuvenate and minimalize the contaminants.

A remote bleeder is nice and convenient but not all of us are willing or able to put a remote bleeder in or quite honestly I don’t know if you can even get one installed without tearing the torque tube and clutch out. So what can we do that is not too labor intensive and wont cost much? Or How can we optimize this system and make it last? Whether its the basic STOCK clutch setup or a rather expensive aftermarket clutch this should only help. We are going to tell you how we do it in the car without too much labor.

The easiest way that we have found is to pull the intake manifold for the C5 and C6 Corvettes. We have ported hundreds of manifolds so we have become proficient at pulling intake manifolds. (Total time to clean head ports and put it back on about 45min.) This will allow one to lay in and across the engine bay. With your head right at the firewall with a 9mm combination wrench and a light just barely have enough room to see the port, pop off the rubber cap (leave it off) and open it while someone else is depressing the clutch pedal. Bleed it just like a brake system, one person (A) holds pedal, the other (B) opens the port till fluid pours out and then closes, (A) pumps pedal till firm again and then repeat till fluid is clear, 3-12 cycles. Remember to check the reservoir! Refill it so you do not get any air in the line. Earlier F bodies and GTOs may be accessible from under the car and may not require pulling the intake manifold.

-Open front of the bell housing by removing the plastic panels.
There are 2 black plastic panels that cover the front side of the bell housing. The driver side has a small 3” panel held in place by 1-10mm bolt. The passenger side panel surrounds where the starter engages the flywheel. Disconnect battery; remove the 2- 15mm bolts and push the starter forward enough to pull out plastic panel. Before you reinstall the starter you can benefit from this wide open space. Check out the next step, Compressed air.

Total time will be between 10min and 1hr depending on stock exhaust manifold or headers and adjoining piping and space restraints and if on a lift or on the ground.

I would imagine that the panels were put in there to keep things from getting into the bell housing but the irony could be what was meant to protect the clutch hurt the longevity of it. The Driver side is shielded by the oil filter and the starter on the passenger side. It is quite amazing the amount of air moved by the clutch at idle from the “exhaust” ports of the bell housing, imagine what it would be in CFM@155mph 7k rpm. Ever heard of Smokey Yunicks flywheel supercharger?

Opening the front side of the bell housing is a crucial part of keeping things cleaner and cooler within the clutch. By allowing the front side of the bell housing to ingest airflow we now have a cross flow of air coming in and out of the bell housing and the faster we go the more volume of air through, like a radiator. With greater volume of high velocity air the clutch debris is expelled much more quickly rather than staying in the bell housing longer like the stock stagnant closed-front-entry (or it doesn’t exit but through a tiny hole like earlier Fbodies and GTOs). On our C6Z we even “ported” the “exhaust” side of the bell housing to even more aid in getting the airflow out. Furthermore, after about 7K miles we again cleaned it there was very little debris in the clutch and bell housing area and the fluid was in great shape too.
We feel that this is conclusive that it does keep the clutch much cleaner and cooler. What happens to a radiator when you block its airflow?

One more thing to mention about the GTOs and Fbodies: It has been our experience that the Heat and the clutch debris can very quickly ruin your fun. A few years back we had a ‘05 80K mile GTO with about 390RWHP and bolton’s, stock clutch. The vehicle was at a road course event and as the vehicle heated up it would lose hydraulics and not even be able to execute a gear shift by the end of a lap. We would have to draw out the DIRTY fluid and replace it every lap. (It is unknown how large a role the heat played it is difficult to test independently. When both sides of the bell housing are open it seems that it is no longer an issue.) Now looking back upon those experiences I know we could have resolved or at least greatly extended the proper functioning of the clutch. Since GTOs and earlier Fbodies do not have “exhausts” on their bell housings I would like to machine a few passages in there and see what happens......Now we have done the aforementioned methods to said vehicles and it has helped rather significantly but they NEED is the “exhaust” side opened up. When you take a look at the bigger picture you can see that it needs both clean high speed air in and high speed air out, just like an engine. Having only one side of it is merely half the battle.

-Use Compressed air and brake clean to blow out bell housing
Now that the panels are off you can get in there with a compressed air probe and blow out all the crevices of the clutch. We have been in there for over 10 minutes still finding more areas that blow out clouds or clutch debris. When you think you’ve blown it out enough keeping going. Then rotate the motor over with a breaker bar and do it again till there is no more clutch debris coming out. Next take 2-3 cans of brake clean and spray it all through anywhere you can. Wear a respirator and have some fans going in a well ventilated area; this is not good stuff to breathe in. Reassemble it and go beat the **** out of it.

We have a customer with a 30K mi 600RWHP C6Z that began to have some clutch slippage. We opened up the front side blew out and cleaned out the bell housing and has yet to have the problem again. One thing to consider is the contact surface of the disc and flywheel. If there is a boatload of dust in there, the surface has been compromised. The grip integrity of a clean surface has changed. Now it doesn't lay all the dust out evenly either so there is an even better chance that you will develop hot spots on the flywheel if one area slips on its own dust and another area grabs. Slowly we began to see how one thing leans on another, heat and dust, dust and heat.
ALSO____
This is from the corvette forum, on how to replace/install clutch


http://redshift.homestead.com/files/...ch_install.pdf

YES! That's the way I do it and its a W H O L E lot easier.

Remove the trans and diff as a unit and then remove the TT... The TT is very light and easy to maneuver. I did mine on jack stands on the garage floor!

Reassemble the SAME way!

Some recommendations:

Change the differential output shaft seals at a minimum!!!

Some post to read over the weekend!

C5 Differential Seal replacement: http://forums.corvetteforum.com/c5-g...on-photos.html

- C5, ragtopws6 , Upgrading your C5 rear with C6 Z06 guts, : http://forums.corvetteforum.com/c5-g...-z06-guts.html

- C5, Its_Go_Time, Output Shaft Install - Left and Right: http://forums.corvetteforum.com/c5-t...post1573407966
Info by; Bill Curlee

Time for a C-5

I have a season with a Level 2 Monster and I like it. I got the steel flywheel and new slave and kept the factory master. Slightly heavier then stock pedal, nice engagement - no issues for me on a mild heads/cam street set-up. The guys at Monster recommend the steel flywheel for street driving and drag racing, and the aluminum for auto-xing. But, this clutch IS NOT recommended for use with NO2. Per the website "...we do not recommend them for turbo or nitrous applications, the torque spike often associated with these power adders is not favorable for Kevlar frictions".

peterskunk

thanks you all for the feedbacks, this is a very knowledgeable group!!!!

I got the Fidenza V2 kit with the light weight flywheel, now i am doing my homework about slave master and slave itself.
not shure if i need everything, but i think if everything will be out, i think is a good idea to put them new.

Slave Master cilinder & slave options??

Time for a C-5

Definitely the slave while it's apart. You can change the clutch master after the fact, if needed.