[Abubaca]

"Clutch Chatter" is an actual term for when your clutch grabs, then slips, grabs/slips/grabs/slips over and over, very quickly, typically during first or reverse gear engagement since it's under the most stress to move the car. You definitely FEEL it, not hear it. It can be caused by many things such as oil or contaminants on the friction surface or uneven wearing and hot spots. It is NOT normal. Sometimes, especially with twin discs, you'll HEAR, what can ironically only be described as....a chatter.....when not fully engaged. It's slack between the moving parts non being engaged, and this is quite normal. This is not considered "clutch chatter". ....though yes...it does sound like chattering.

[Coded4SS]

Originally Posted by Abubaca

"Clutch Chatter" is an actual term for when your clutch grabs, then slips, grabs/slips/grabs/slips over and over, very quickly, typically during first or reverse gear engagement since it's under the most stress to move the car. You definitely FEEL it, not hear it. It can be caused by many things such as oil or contaminants on the friction surface or uneven wearing and hot spots. It is NOT normal. Sometimes, especially with twin discs, you'll HEAR, what can ironically only be described as....a chatter.....when not fully engaged. It's slack between the moving parts non being engaged, and this is quite normal. This is not considered "clutch chatter". ....though yes...it does sound like chattering.

Agreed. But good luck trying to get a dealer to do anything. "It's a wear item" "it hasn't failed" "it needs to be in pieces" are all things they told me. Shop foreman wouldn't even stop doing a tire rotation so he can test it out himself.

[TRZ06]

Mine does it too. It obviously is quite common and I doubt a major issue. Whether it should or not, it sounds like an inherent charactistic since it is quite common.

I wouldn't worry about it, that is what a warranty is for.

Mine only does it if I give it just enough gas to keep from stalling when engaging 1st gear. If I add a little more throttle and let the clutch out a little quicker, it doesn't do it at all.

[m6-lt1]

Originally Posted by TRZ06

Mine only does it if I give it just enough gas to keep from stalling when engaging 1st gear. If I add a little more throttle and let the clutch out a little quicker, it doesn't do it at all.

I think I can say the same as well. If I'm a little quicker and give more gas, it won't do it. If I'm slow and barely give gas, it might do it. 43k on my car.

[zx9rmal]

I also have it on my ZL1.

[DorkMissile]

Most of the time this is the discs getting glazed - which can be from quite frankly letting the clutch out too slow at too high of a RPM. It ends up polishing the discs

The clutch and trans setups in these cars are very robust and heavy duty, however (and I was guilty of this too) if you grew up driving regular commuter cars that were manual trans, you get accustomed to feathering the clutch a lot, which teaches you some bad habits, which in turn leads to problems here when you have a real heavy flywheel, a fairly heavy spring, semi-metallic discs and almost NO pedal feel that engages way too far off the floor.

I think the stock clutch works well, but there is absolutely no feel, so you end up hunting (or at least I did) for the engagement point.

For myself - what I eventually did was made a pedal stop. I screwed two hockey pucks together - used heavy duty double sided tape to affix them to the firewall. I took the rubber pedal cover off, drilled a small hole and bolted on to the pedal a elevator bolt with an adjuster and jam nut. I eventually thru trial and error got the stop set so when the pedal was down, it was about 1/2" past full disengagement. (I also had to "relearn" the clutch pedal travel using HP Tuners).

Once I did this, I was much more consistent driving the stock clutch (and launching the car at the track) as I was using the feel of the pedal against the stop vs hunting for the grab point which was floating out there way off the floor. Basically, once the pedal came off the stop, the car began moving.

Now over the winter I did a major build to the engine, so I upgraded the clutch to a Tilton ST-246 and Tilton throw out bearing. Upon doing this - and I think it is the throw out bearing that made the change - the grab point changed. I had to take my pedal stop out and relearn the clutch in the ECU again, but the grab point is much closer to the floor. Not saying everyone needs to upgrade clutches, but there is something about GM clutches where the grab point is in a weird spot for me.

Now one thing here to consider is that on the OEM throw out bearing, the bearing itself is not a real heavy duty item and is mounted to the input shaft on a plastic bushing. It all works smooth when new, but with any use it begins to bind, and will get worse and worse. I will say I was pretty aggressive with mine, but at 14k miles, the bearing was almost toast and the bushing was binding (you couldn't move it real smoothly on the shaft by hand).

Tick Performance makes an Aluminum bushing that allows for a little grease in it, which is the hot ticket with a stock TOB, but I would not tear the trans out to put one in on a used TOB. You would tear it apart, but a new TOB and install the Tick sleeve in the new assembly.

And by the way - nobody makes a replacement bearing for the GM slave cylinder (most cars you can). Rumor has it that there is the same bearing that GM used on many Saab cars, but you can't get the bearing in the US. Have to buy it and ship it from Europe.

By the time you spend all that money you could just replace it with the Tilton or Hayes slave / TOB assembly (which have serviceable bearings)

[Whitespeed]

Originally Posted by DorkMissile

The clutch and trans setups in these cars are very robust and heavy duty, however (and I was guilty of this too) if you grew up driving regular commuter cars that were manual trans, you get accustomed to feathering the clutch a lot, which teaches you some bad habits, which in turn leads to problems here when you have a real heavy flywheel, a fairly heavy spring, semi-metallic discs and almost NO pedal feel that engages way too far off the floor.

I think the stock clutch works well, but there is absolutely no feel, so you end up hunting (or at least I did) for the engagement point.

For myself - what I eventually did was made a pedal stop. I screwed two hockey pucks together - used heavy duty double sided tape to affix them to the firewall. I took the rubber pedal cover off, drilled a small hole and bolted on to the pedal a elevator bolt with an adjuster and jam nut. I eventually thru trial and error got the stop set so when the pedal was down, it was about 1/2" past full disengagement. (I also had to "relearn" the clutch pedal travel using HP Tuners).

Once I did this, I was much more consistent driving the stock clutch (and launching the car at the track) as I was using the feel of the pedal against the stop vs hunting for the grab point which was floating out there way off the floor. Basically, once the pedal came off the stop, the car began moving.

Couldn't agree more about the clutch pedal feel. I just installed a Hays Clutch Pedal Height Adjuster this past weekend and it has made a world of difference. I'll be doing a detailed write-up on it in a separate post, but in a nutshell, the engagement point is now closer to the floor and feels much more natural to me, having significantly less dead zone before engagement. Similar idea to what you accomplished with hockey pucks. But, I'm very tall, and I think the reduced pedal travel with a setup like that may have bothered me.

Nigel

[ctrlz]

Originally Posted by jeep_junkie

Well I had my car checked out by the dealer. The drivetrain tech told me quite categorically that the clutch should not shudder at all. They took it apart and found that the shudder was due to uneven engagement as the pressure plate fingers were uneven. I got a new clutch under warranty and it is buttery smooth now.

Good story and glad you pursued it. I don't think a stock clutch should shudder. Maybe if you go aftermarket with higher clamping force, but not stock.
So, I wonder if this got banged on the assembly line. I bet they have them stacked and then they get loaded onto some kind of jig which bears the weight while the tech installs the parts. Either it was dropped, something fell on it, or it got smashed into something while being installed. Those diaphragm fingers are very strong.

[Frankie18SS]

Originally Posted by Coded4SS

Agreed. But good luck trying to get a dealer to do anything. "It's a wear item" "it hasn't failed" "it needs to be in pieces" are all things they told me. Shop foreman wouldn't even stop doing a tire rotation so he can test it out himself.

You seriously need to go to another dealership. Like everyone else said, it can be noisy but I only really hear it in a parking garage. You shouldn't be able to feel it.

[6spdhyperblue]

Unless you cooked it of course

[Coded4SS]

Thanks for info guys
Nah I didn't do this to the car it was like this off the dealer. I've driven 6 manual cars over 15 years and never had chatter.
Tech recognized it was there but in the scenarios we created it was minimal but I did feel it. Overall it wasn't enough for them to warrant changing it I guess. Kinda sick of these dealers if Chevy didint have a v8 manual I wouldn't be here.

So really idk what to do. Some say normal some say it's not. My only option is to take it to a dealer hour and a half away and get their opinion. Really appreciate that info

[AmazinglySmooth]

I experience this but I consider it rare. For my 1LE, I park it on a hill regularly and have to reverse initially. This can happen, but I avoid it by revving just a bit higher. I haven’t tried to repeat it, but I feel like I can avoid it by revving just a bit more than other manuals I have had.

[Coded4SS]

Ive played with it. Even if I raise the rpm if I get the clutch to where it's just starting to mate is where it happens.

[cdrptrks]

I have experienced it before but it is very rare now that I have learned to start off in a way that doesn't trigger it. I think a brand new clutch would probably do the same thing.