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LS7 clutch - possible problem?

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Old 02-15-2012, 03:40 PM
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The Evil Genius
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St. Jude Donor '08-'09-'10-'11

Default LS7 clutch - possible problem?

Put this over in the Z06 forum, but thought I'd get a wider audience here.

I installed an LS7 clutch in my Z06 recently. It works really well, if a little low on the engagement point (close to the floor). 1-6 work perfectly fine, but occasionally reverse grinds just slightly and the car bucks. Once there's that small grind and clunk, it goes into gear and is just fine. I can let off the brakes, and the car doesn't move until I let out the clutch so it's fully disengaged.

So do I have a clutch issue (do I need an adjustable master? I have stock C5 hydraulics) or a trans issue?

Thoughts?

Will
Old 02-16-2012, 05:23 PM
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The Evil Genius
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St. Jude Donor '08-'09-'10-'11

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Anyone have any thoughts on the matter?
Old 02-16-2012, 06:54 PM
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C5FORFUN2
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1-6 are synchronized, reverse isn't. Sounds like you are not getting full disengagement. Possibly need to bleed the clutch system to remove air or the clutch master is going bad and bypassing internally. I don't know how to test it before replacing, but someone on here probably does.
Old 02-16-2012, 08:54 PM
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bleed the clutch. you should have installed a remote clutch bleeder while you were in there. it is possible to install one with out removing the transmission.
Old 02-17-2012, 11:38 AM
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The Evil Genius
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St. Jude Donor '08-'09-'10-'11

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Remote clutch bleeder is installed, clutch was bled twice. I like to be thorough, so I ran clear, then super blue through the clutch. I could try again, I suppose. Clutch engagement is very close to the floor, which it seems is common for LS7 clutches on C5's.

So assuming that there isn't an air problem, if I'm not getting full disengagement, do I need an adjustable master? The slave is brand new, the master has less than 20K miles on it, new when I replaced it.
Old 02-17-2012, 11:51 AM
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Hi,
I have a LS7 clutch in my C5 and it ingages like the stock one.
Do you have a lot of play on the pedal?
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Old 02-17-2012, 01:00 PM
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feeder82
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mine works like the stock one also, maybe even smoother. grabs where it should
Old 02-17-2012, 01:41 PM
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The Evil Genius
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Not a lot of play, no. The engagement point is almost right off the floor, less than an inch of travel from floor to starting to grip. It may be fine, since the car was down for over a month I could simply be forgetting how it used to feel. It's easy enough to drive, so I'm not worried about that.

The reverse thing is weird, very sporadic.
Old 02-17-2012, 07:16 PM
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JonLT4CE
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I had the LS7 clutch in mine over a year ago. Mine engaged quickly on the floor as well. It will resolve over time - about 7 months of use. Mine is "Nornal" now.

-Jon
Old 02-18-2012, 07:47 AM
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I installed one in my '99 Coupe. It too engages about an inch off the floor. Seems to work just fine though.
Old 02-20-2012, 01:13 AM
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St. Jude Donor '03-'04-'05-'06-'07-'11

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Hi Evil Genius -

I have an LS7 clutch with c5 Z slave and master cylinder and it feels just like the stock C5 clutch did, and the engagement is not near the floor -

I would heed the advice above and bleed the system again, and re-check all of the obvious things. Something is not right if the pedal travel is that far to the floor.

best

mqqn
Old 02-20-2012, 04:02 AM
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Well it seems that a lot of people have put the LS7 Clutch into their C5 I also have done this. Here what some of the GM-Tech guys have told me that the LS7 Clutch is thinner then the Stock C5 clutch set-up. Their are some guys who have made a spacer plate that is about .160 thousands thick (JUST UNDER 3/16 OF A INCH) it helps the Clutch a lot. You can try and Contact Richie @ Abel Chev. in Cali. I believe he has them in Stock worth doing.


Pops
Old 02-20-2012, 11:41 AM
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did you replace the slave with the new clutch? maybe a dumb question, but it needs to be asked :P.

Also, have you played around at all with the shifter alignment?

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