Problems with LS7 Clutch In C5?
Thread Starter
Burning Brakes
Joined: Feb 2013
Posts: 749
Likes: 13
From: SoCal CA
Problems with LS7 Clutch In C5?
I've been looking for a shop to install new clutch in '03Z. One place tried to talk me out of using the LS7, claiming he can't shim the LS6 TOB to give proper pedal height. He's trying to talk me into using the LS6 clutch instead. Any truth to this? Or just laziness?
Team Owner
Joined: Oct 2000
Posts: 29,937
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St. Jude Donor '03-'04
Cruise-In 1-2-3-4-5 Veteran
Plenty of us have installed the LS7 clutch. I upgraded the hydraulics to the LS6 cylinders and also the LS7 flywheel. The kit you can get from GM Parts House, among others, seems to let just about any shop do the job. I had mine put in by a local Chevy dealer's service department and they didn't screw up anything, except the shifter realignment.
The new clutch setup starts out with the pedal VERY close to the floor but it comes back up to normal or thereabouts after driving around for a while.
The new clutch setup starts out with the pedal VERY close to the floor but it comes back up to normal or thereabouts after driving around for a while.
Team Owner
Joined: Oct 2000
Posts: 29,937
Likes: 22
St. Jude Donor '03-'04
Cruise-In 1-2-3-4-5 Veteran
Lionel, I put in mine as a stepping-stone to More POWAH!
An John, Lionel is right, the LS7 clutch and flywheel *are* heavier and you'll actually make your car a tad slower to respond until you add more power.
An John, Lionel is right, the LS7 clutch and flywheel *are* heavier and you'll actually make your car a tad slower to respond until you add more power.
Thread Starter
Burning Brakes
Joined: Feb 2013
Posts: 749
Likes: 13
From: SoCal CA
I know the '04 LS6 cylinders were improved, and would use one. I planned on getting the GMPH kit with clutch, pp, tob, and slave. The shop told me that the LS7 would have a low pedal. I was just wondering if it was a real concern, or he didn't want to bother shimming it. If it returns to normal height after break-in, I guess it's no problem.
Thanks for the reply,
John
Thanks for the reply,
John
Thread Starter
Burning Brakes
Joined: Feb 2013
Posts: 749
Likes: 13
From: SoCal CA
I didn't realize there were downsides to the LS7. My '03Z06 is stock right now, and I don't plan on adding much more than a cam and headers in the future. Maybe I would be better staying with the LS6 clutch.
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
There are alternatives to oem. First no one stops adding hp. It is an addiction. Second a Z already having the good flowing heads can make real good power with cam, headers, and a good tune. I would imagine if you go with a stock LS6 clutch you will be going back into it in a few years.
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
How long the clutch will last is more a function of how you drive it. Most of the OEM C-5 clutch problems you read about on the forum have been exaggerated and are a result of improper installation or just ignorance on the part of the owner with regards to troubleshooting. My 01Z with 80k+ miles has been auto-crossed and has participated in numerous HPDE events since new and it is still on the original clutch.
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Drifting
Joined: Feb 2005
Posts: 1,298
Likes: 21
From: east taunton ma
It's not the stock clutch wearing out as much as the problems come from the slave cylinder leaking and needing to be replaced. If you have to replace the slave cylinder you should replace the clutch while your there and upgrade the hydraulics to the LS 6 hydraulics. I used the LS7 clutch kit and had 0 problems
Burning Brakes
Joined: Jun 2012
Posts: 1,240
Likes: 1
From: Orange County California
I like my LS7 clutch...dunno why your guy is pushing an LS6 on ya in that way....he may have an LS6 takeoff clutch laying around and is trying to unload it and make a few bucks...who knows....pedal effort seems like stock on mine.
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
When my slave leaked at 100,000 miles on my '03 Z06, I replaced it with stock. I considered upgrading to aftermarket or LS7 but I also considerd any possible negatives, however slight they may be. I decided that other than the leaking slave, I was having absolutely no problems with the clutch itself. I do have some mods done underhood and I run the car on the dragstrip ocassionally and also drive somewhat aggressively. I figured if the original clutch lasted 100k trouble-free miles, I'd just replace with stock. Since the new components are upgraded since '03 they should last at least as well. It's over a year plus now and the clutch works perfectly and has given me no problems at all.
Melting Slicks
Joined: Jan 2004
Posts: 3,012
Likes: 15
From: Jensen Beach FL
When I replaced my clutch in my LS1 the master tech at the Dealer talked me out of the LS7 set up. Said he would not guarantee proper results but he said the LS6 was an approved GM replacement so I went with the LS6 set up and have had no issues. I did not want to risk the $$$ on parts and install. I know lots of forum member have gone with the LS 7 set up without issues but I have heard a few issues with early pedal engagement. Now that I know the LS7 PP is heavier and I do not plan on any future HP gains I am glad I went with the LS6 clutch and PP.
Thread Starter
Burning Brakes
Joined: Feb 2013
Posts: 749
Likes: 13
From: SoCal CA
That, seems to me, should be standard practice. I believe the service manual calls for it. If the slave has adequate throw, it should only be a matter of selecting the right size shim. I guess some shops don't want to take the time. I'm not in a great hurry yet. The slave had sticking problems and was flushed, and three months later it's only starting to get hard to shift. I just want to have a plan ready for when the fateful day comes.
Thanks for all the support,
John
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
I don't think it's an issue for an ls1 or ls6 clutch kit. I don't beleive any c5's came from the factory with a shimmed slave/TOB. I think this is mostly for aftermarket clutches. FWIW, my LS6 clutch/pp ended up not needing a TOB shim.
Le Mans Master
Joined: Oct 2003
Posts: 6,126
Likes: 19
From: Streamwood illinois
I've used a stock ls7 clutch/flywheel without shimming w/ ls6 slave without issue. At least 100 sub 1.7 60' passes deep into the 11s on an 18" drag radial. Pedal effort is stock and my 5'2" gf has no problems driving it. Best of all no sticky pedal like the pos ls6 setup.
Last edited by T_Vert; May 7, 2013 at 04:19 PM.
Pro
Joined: Jun 2012
Posts: 633
Likes: 0
From: Van Buren Arkansas
I went to tickperformance.com and bought the Monster Stage 2 clutch w/ the 18lbs Flywheel. I bought the kit that included the slave cylinder, Tick Master cylinder, ARP bolts, and speed bleeder and it's the best thing I've ever put in my car. My friend put an ls7 clutch in his 01' z and I liked the way mine felt and drove tons better. Of course that's merely an opinion, but I've really enjoyed this clutch so far. It's rated for 550rwhp and I'm at 353rwhp so it should last me some good time too lol. Check with Tick Performance to get a good complete package of whatever brand, they usually have good prices. Good luck! 
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
In my 346 biuld I ran an LS7 clutch with an aluminum flywheel at 460RWHP. I loved that setup. Felt like stock - which it should.