jss06c6

Guys,

Have 20K miles on my 2010. There is some mild "shudder" upon engagement of the clutch when taking off in first gear. Not bad, but would not expect to have this with a dual disk. Have had the vehicle for about 2 months now and has had this symptom since I picked it up. Is this normal for the LS9 clutch?

Don't want to tear in to anything that doesn't warrant it, so would like ot hear from the rest of the ZR1 team. My '06 LS2 was smooth, but it was not a dual disk, obviously.

C5kid

no, should be smooth. How dark is your clutch fluid? I may help to do the "Ranger" method and change the fluid if it is dark.

I generally change my fluid every 3k, because it does make a difference

911/Q45

The first owner probably overcooked the clutch and that would cause the shuddering.

jss06c6

Master cylinder reservoir was "dry" when I picked up the vehicle. Have completely purged system with DOT4, all clean. Never any issues with pedal stroke or feel, just upon engagement, there is a minor shudder. I can slow down and slip it a bit more and avoid it, but normal engagement shows same issue. Vehicle did not show any signs of hard use and is 100% OEM.. All other fluids clean. Vehicle maintenance records show dealer oil change at 17K miles, so all good there.

911/Q45

All he had to do was slip it too much on a hill start and that would be enough to glaze it, too bad.

timmyZ06

it does sound like a glazed clutch, sorry, mine is smooth no shudder

whatcop?

How many miles have you put on it since you got it? Especially how many city miles.

OnPoint

Make a couple semi-hard launches, with some time in between them, and you might be able to "clean up" the clutch if it's glazed.

whatcop?

City drive it and it will clean up

jss06c6

Have put about 600 miles on it. Limited city driving so have not ridden clutch that much. Would not expect a hard launch to cure it if it truly is glazed. Does seem a bit worse cold than hot. Don't believe I could make this a warranty issue. I've been building cars for almost 40 years and would not have expected this clutch to exhibit glazing, which I always attribute to overheating due to aggressively slipping the clutch for extended periods. Would think this dual disk would be more robust.

jss06c6

Ok will put some miles on it and see how it goes.

whatcop?

Mine would do the same thing after going to the dragstrip. If I drove her in the city quite a bit she would smooth back out.

pcguy2u

Does seem kind of strange that the master cylinder was dry. Was/is there any sign of fluid around the bottom of the engine? Where did that fluid go?

jss06c6

My son and I discussed the same thing (re: where did the clutch fluid go).. There is no sign of leakage at all. Completely dry around clutch housing. No sign of a slave cylinder leak. All I can figure is the guy never serviced the clutch. Has not dropped a bit since purging with DOT4. Will keep an eye on it. I wondered if some clutch fluid leaked out into the disk and pressure plates causing a bit of slippage. Would need to tear into it to see if that's the case, but not bad enough for that much work right now. Will definitely keep an eye on it for any drop in level.

pcguy2u

That was my thought. If there is a leak and it's ending up on the disk(s), it's a warranty issue