LS7 Clutch question
Thread Starter
Instructor
Joined: Dec 2013
Posts: 175
Likes: 8
From: Tuskegee Al
LS7 Clutch question
Greetings!
I am about to undertake my clutch install as soon as the weather breaks down here. I have all parts with the exception of the torque tube seals, which are scheduled for Wednesday. I have my LS7 clutch kit, a Dorman slave cylinder, a GM master cylinder and a Tick performance remote bleeder. I also have the rear main seal kit and a centering tool as well as a new barbell. I have the Tick Performance torque Tube rebuild kit. My latest question is I have read that the LS7 clutch kit comes balanced, with a mark on the flywheel and on the pressure plate. However, the marks do not line up exactly. Do I install it as close to the marks as possible, or do I seek another solution? All advice will be appreciated.
I am about to undertake my clutch install as soon as the weather breaks down here. I have all parts with the exception of the torque tube seals, which are scheduled for Wednesday. I have my LS7 clutch kit, a Dorman slave cylinder, a GM master cylinder and a Tick performance remote bleeder. I also have the rear main seal kit and a centering tool as well as a new barbell. I have the Tick Performance torque Tube rebuild kit. My latest question is I have read that the LS7 clutch kit comes balanced, with a mark on the flywheel and on the pressure plate. However, the marks do not line up exactly. Do I install it as close to the marks as possible, or do I seek another solution? All advice will be appreciated.
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Le Mans Master
Joined: Aug 2005
Posts: 7,392
Likes: 218
From: Merritt Island, FL
Good info above. Perhaps it's fine to use as is. But, I still question, how do you know how to align the pressure plate with the flywheel? Is it indexed in some other manner to prevent improper orientation?
Le Mans Master
Joined: Oct 2012
Posts: 9,366
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From: Out back
Since when the hell does a single plate clutch need to be "balanced" or "matched" to a flywheel? That's what the alignment dowels are for. I've done two dozen or so clutch jobs on various cars (even some true rotating assembly dynamic stuff) through the years (and on both of my ZO6s) and never once, was that a thing. If that WAS even a thing, the moment you took it apart to install it, it would introduce imbalance. Not to mention, the friction disc, TOB, etc. and their imbalance introduced into the picture. What tool even exists to "balance" a clutch and flywheel that are bolted together on a spinning crankshaft?
@OP, bolt her in, torque them down, check your TOB measurements, and go. Paint marks are ambiguous to say the least. Unless you're pulling the rotating assembly out entirely to do a full dynamic balance, there is ZERO reason to be concerned...especially when replacing with an OEM clutch assembly.
@OP, bolt her in, torque them down, check your TOB measurements, and go. Paint marks are ambiguous to say the least. Unless you're pulling the rotating assembly out entirely to do a full dynamic balance, there is ZERO reason to be concerned...especially when replacing with an OEM clutch assembly.
Le Mans Master
Joined: Aug 2005
Posts: 7,392
Likes: 218
From: Merritt Island, FL
It's not the disc. It's the pressure plate which remains fixed to the flywheel.
The C5 is quite sensitive to vibrations as a result of the torque tube / rear trans design. Extra steps were taken in the flywheel balance in original assembly to prevent this.
The C5 is quite sensitive to vibrations as a result of the torque tube / rear trans design. Extra steps were taken in the flywheel balance in original assembly to prevent this.
Le Mans Master
Joined: Feb 2021
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From: Florida
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There was some balancing done on the original clutch set, and if removing and later reinstalling it you are supposed to mark the components and put it back the same way.
If you have a GM LS7 clutch kit just bolt it in and you’re good. Some have been reported to vibrate, but that’s an outlier.
I checked Amazon and the only authentic GM LS7 clutch kit I found was the clutch and pressure plate only; no flywheel. Are you certain it is GM, or is it “GM OEM” ? If it’s OEM, it’s probably a Luk brand, which is not all bad, in fact I believe they manufacture parts for GM. Still, even if it’s a Luk, I hope you got a complete set including flywheel and pilot bearing.
You must use a matching LS7 flywheel with this clutch.
If you have a GM LS7 clutch kit just bolt it in and you’re good. Some have been reported to vibrate, but that’s an outlier.
I checked Amazon and the only authentic GM LS7 clutch kit I found was the clutch and pressure plate only; no flywheel. Are you certain it is GM, or is it “GM OEM” ? If it’s OEM, it’s probably a Luk brand, which is not all bad, in fact I believe they manufacture parts for GM. Still, even if it’s a Luk, I hope you got a complete set including flywheel and pilot bearing.
You must use a matching LS7 flywheel with this clutch.
Last edited by vette4fl; Jan 20, 2022 at 11:02 PM.
Melting Slicks
Joined: Jan 2000
Posts: 3,326
Likes: 523
From: home
LS7 clutches, from GM, come as a pressureplate/disc only and the flywheel separately, not like a C5 that come as an assembly. I've done a few LS7 clutches using a Ram flywheel with no vibration issues..
Thread Starter
Instructor
Joined: Dec 2013
Posts: 175
Likes: 8
From: Tuskegee Al
Greetings;
I appreciate all of the input regarding this clutch kit. I am currently dealing not with paralysis of analysis but paralysis due to weather. It is 27 degrees here in south Alabama and I am chomping at the bit to get this project started. I did recognize that iI purchased the wrong master cylinder and I returned it for a Luk unit. Now I am anxious to measure the slave cylinder gap to make sure we can install without too many complications. I will update as we go along.
I appreciate all of the input regarding this clutch kit. I am currently dealing not with paralysis of analysis but paralysis due to weather. It is 27 degrees here in south Alabama and I am chomping at the bit to get this project started. I did recognize that iI purchased the wrong master cylinder and I returned it for a Luk unit. Now I am anxious to measure the slave cylinder gap to make sure we can install without too many complications. I will update as we go along.
Melting Slicks
Joined: Jan 2000
Posts: 3,326
Likes: 523
From: home
Keep in mind this will be heavier than the C5 setup if you are planning on using a C6 flywheel. I use a Ram 2552 aluminum wheel with LS7 clutches to get the weight down. You will also need to loosen the bell housing to fit the pressure plate and disc.
Thread Starter
Instructor
Joined: Dec 2013
Posts: 175
Likes: 8
From: Tuskegee Al
I have the cast iron LS7 flywheel from the kit. The shipping weight for the kit was around sixty pounds. I might have to use the floor jack to lift it into position. I will update when we get there.