# New LS7 Clutch Experience



## gurvinerjeff (Jan 9, 2009)

Well, I recently had to rebuild my 2005 M6 (syncros mostly, and output bushing, also a new slave and bearings) and the rebuilder called me about my burnt original LS2 clutch. I did not then have the $ to replace it so after some resurfacing it went back in. Now, 3 months later, I bought an LS7 (gmpartshouse) and Tick clutch slave bleeder and had them installed. After about a week and 150-200 miles (my daily driver), the clutch engagement came up off the floor and all is well. I got on it this am on the onramp, went through 3 gears and had no trouble shifting. No spongy clutch; no grinding of the gears, just good hard acceleration and smooth shifting. At home I saw where the installer placed by bleeder and redid it. I bled it again just to see how the Tick "one man bleed" worked - great addition.

So, my conclusion concerning LS2 clutches, dirty fluid, and spongy high rpm shifting is that the weak clutch is the central issue. Now I say this concerning my stock drive train (exception is one-piece drive shaft). Once the original LS2 clutch starts to slip, it heats up the pressure plate, weakens the springs, boils the clutch fluid, and the problems start. I do not believe that simple clutch hydraulics repairs/replacements/bleeding is the solution. It starts with the weak OEM clutch. With the LS7, there is no slipping, no heating, no boiling fluid. I recommend that any one with an OEM LS2 clutch replace it with the LS7 or something similar. Sure, there are probably some of you with the original clutch that have no problems. But the bulk of us need that thing replaced.


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## 87GN06GTO07IRL (Aug 10, 2009)

LS7 clutch is a great bang for the buck on these cars.


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## jpalamar (Jul 22, 2008)

Sounds more like the owner destoryed the car then the stock clutch is that horrible. Don't see too many stock powered LS motors destroying a T-56 trans... 

I'm assuming you just forget to mention it, but you did replace the slave and TO bearing while there right?


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## Gotagoat (Jan 6, 2006)

Constant aggressive shifting, riding the clutch, and/or poor shifting technique will ruin a clutch sooner than later. How many miles did yours have on it when it went south? I haven't read too many complaints about the stock clutch so I'm wondering if this is a common issue.


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## BlackJackByte (Aug 31, 2009)

Gotagoat said:


> Constant aggressive shifting, riding the clutch, and/or poor shifting technique will ruin a clutch sooner than later. How many miles did yours have on it when it went south? I haven't read too many complaints about the stock clutch so I'm wondering if this is a common issue.


Somewhat new to M6 as of a couple years ago. What would you describe a poor shifting technique as?


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## jpalamar (Jul 22, 2008)

BlackJackByte said:


> Somewhat new to M6 as of a couple years ago. What would you describe a poor shifting technique as?


Going 30 MPH in 3rd or 4th and then dropping it to 1st to take off without rev matching is an easy way to wear syncros. Just an example.


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## Gotagoat (Jan 6, 2006)

I'd say not fully depressing and/or releasing the clutch; 'popping it' - letting your foot slip off the pedal a few inches from the top; 'slidding the shift' -- releasing the clutch too slowly when shifting. Really anything other than a smooth release.
I'm not saying every shift has to be textbook perfect - because mine sure aren't - only that anything else tends to wear the clutch more quickly.
Yes, as stated above, failing to match revs is also hard on the clutch and trans.


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## gurvinerjeff (Jan 9, 2009)

jpalamar said:


> Sounds more like the owner destoryed the car then the stock clutch is that horrible. Don't see too many stock powered LS motors destroying a T-56 trans...
> 
> I'm assuming you just forget to mention it, but you did replace the slave and TO bearing while there right?


I got the car as a theft recovery with 5000 miles. The clutch has problems from the start but got worse over time. The car had 48k when the tranny was rebuilt - the main reason was the tail shaft bushing was loose and the driveshaft has a slight wobble. The tranny was not "destroyed". I did mention the slave and bearing in line2.


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## Gotagoat (Jan 6, 2006)

That explains a lot. It sounds as if the thieves put the white heat on the clutch/drivetrain and significantly shortened its life. Which brings up again the question of whether clutch problems are common. I have only 25K miles on mine and I'm easy on it. So far, no problems. However, when it does need to be replaced, I'm reading here that the LS 7 may be a better choice than an OEM.


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## BlackJackByte (Aug 31, 2009)

Ok cool thanks for explaining. Sometimes ill be in 4th and drop to 3rd and the car will kinda "bow down" and you'll hear a little whine...is that pretty hard on it? I think I may be a little slow when releasing the cluctch but I don't think anything too crazy so that shouldnt be too bad should it?


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## jpalamar (Jul 22, 2008)

Gotagoat said:


> That explains a lot. It sounds as if the thieves put the white heat on the clutch/drivetrain and significantly shortened its life. Which brings up again the question of whether clutch problems are common. I have only 25K miles on mine and I'm easy on it. So far, no problems. However, when it does need to be replaced, I'm reading here that the LS 7 may be a better choice than an OEM.


LS7 is way better then the stock replacement, and I belive its cheaper too 

I'm at 68k miles on my stock clutch. I have just shy of 100HP over stock to the wheels. I drive bumper to bumper for 25 miles to work M-F and do alot of spirited driving on weekends. Still holding up fine, but I'm sure its a ticking time bomb.



BlackJackByte said:


> Ok cool thanks for explaining. Sometimes ill be in 4th and drop to 3rd and the car will kinda "bow down" and you'll hear a little whine...is that pretty hard on it? I think I may be a little slow when releasing the cluctch but I don't think anything too crazy so that shouldnt be too bad should it?


That doesn't soudn bad. Its only people who are going 4-2, 4-1 when the RPMs are jumping a ton that it really makes a difference. You can smooth the downshifting by bliping the throttle right before you let the clutch out that way the RPMs go up and car doesn't get the bucking/bowing feel.

I wouldn't worry about it though.


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## Gotagoat (Jan 6, 2006)

jpalamar said:


> LS7 is way better then the stock replacement, and I belive its cheaper too
> 
> I'm at 68k miles on my stock clutch. I have just shy of 100HP over stock to the wheels. I drive bumper to bumper for 25 miles to work M-F and do alot of spirited driving on weekends. Still holding up fine, but I'm sure its a ticking time bomb.
> 
> ...


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