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Discussion Starter #1
Hey guys,

I could really use your advice. I have been experiencing an issue with the clutches ability to "grab" after it warms up. I do a lot of stop and go driving on the way home from work. It takes me about 45 minutes to an hour to drive roughly 14 miles. Anyway, the other night, I was on a fairly steep incline, TC was off making a turn. I let out the clutch fairly quickly and was going to make a "semi" aggressive launch when the rpm's shot almost to redline at which point I shifted into 2nd to have the same thing happen. I wasn't really moving and I glanced back to see smoke, not from the tires. I had the smell of burnt clutch. I babied her home and let it sit. I then drove to the dealership first thing in the AM. There was a little bit of slipping, but nothing like it was and you really had to watch the tach. Anyway, the dealer let the car sit and then had 3 people take it out for a drive. They all said that they didn't notice anything; however, they drove it with the TC on. No smell either. I then went and test drove the car with the service manager, turned the TC off. I got a little bit of the smell when I made a semi aggressive launch, but because the car had cooled it really wasn't noticeable. He said that he would call the GM tech line and speak to them. Can anyone offer advice or input?

Thanks!!!
 

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Discussion Starter #2
Wow, I am surprised. 89 views and no one has any ideas? I guess I have a couple questions then...

Is there an inspection cover or something that the clutch plate can be measured to see if the surface has been reduced?

What was the reason that after starting initial production of these vehicles did GM decide to change to DOT 4 fluid instead of DOT 3?

Could some of the issue that I am experiencing have to do with the clutch fluid being in close proximity to the cats?
 

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MattSaint said:
Wow, I am surprised. 89 views and no one has any ideas? I guess I have a couple questions then...

Is there an inspection cover or something that the clutch plate can be measured to see if the surface has been reduced?

What was the reason that after starting initial production of these vehicles did GM decide to change to DOT 4 fluid instead of DOT 3?

Could some of the issue that I am experiencing have to do with the clutch fluid being in close proximity to the cats?
I remember there being an issue about the clutch fluid on the 2001 Z06 Vettes. Seems that the fliud was too close to exhaust and would heat up & then no clutch action. They revised the line routing I think but not sure if it was all 01s or just early. You can check it out on Z06vette.com and probably find the info.Hope it helps you. Craig
 

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Well, the only thoughts I had were questions. Was your car affected by either of the 2 clutch TSB's - bolt torques or clutch slave change? Have either of those been worked on?
I also take about 30 minutes to go 12 or so miles - and I haven't experienced any similar experience.
Dan
 

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Have you checked for the ok mark on the back of the driver side cylinder head should be the letters OK in yellow paint. Sounds like something they will have to fix .You could try a different dealer .some will give you a problem , some are more than happy to help,especially if you have the technical service bulletin numbers.Good luck
 

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I haven't got any real idea what the problem is. Question... Do you have any play in the clutch pedal... meaning any movement before it starts to disengage or is it so close that any touch of the pedal is it starts to slip? I'll check mine tomorrow but your comment about the oil made me think that there's too much oil. Naw, maybe something else.
 

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Knight Errant
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Dished flywheel

MattSaint said:
Wow, I am surprised. 89 views and no one has any ideas? I guess I have a couple questions then...

Is there an inspection cover or something that the clutch plate can be measured to see if the surface has been reduced?

What was the reason that after starting initial production of these vehicles did GM decide to change to DOT 4 fluid instead of DOT 3?

Could some of the issue that I am experiencing have to do with the clutch fluid being in close proximity to the cats?
I have had it told to me that the flywheel on the Manual transmission car has been slightly dished to cushion engagement. If pressed I can probably go find that info again. The point, I guess, is that this is not normal in anything else I have ever owned or driven and sounds to me like a really bad idea, sort of like the TM and Abuse software I have to wrestle with on the A4. It sounds to me like a recipe for frying clutches. Question #1 - No. Question #2 answers Question #3... :(
 

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Discussion Starter #8
Guys,

Thanks for the replies.

I checked and I have the "yellow" Ok on the back of the head. So, I am assuming that the bolts were re-torqued on the assembly line. I also checked and I have the cap on the clutch slave say DOT 4, so again I am assuming that it was changed on the line. Only thing I notice when I start to depress the clutch is some kind of noise. Nothing metal, but almost like a rubber seal opening up. It happens ever time I depress the clutch pedal. I also notice that when it does warm up that it is harder to find a gear. Especially reverse. The last thing I would mention is that around 2.5 to 3k rpm is one the clutch seems to start slipping, but it is a gradual thing. Almost like when you slip the clutch on take offs...
 

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Sounds like

MattSaint said:
Guys,

Thanks for the replies.

I checked and I have the "yellow" Ok on the back of the head. So, I am assuming that the bolts were re-torqued on the assembly line. I also checked and I have the cap on the clutch slave say DOT 4, so again I am assuming that it was changed on the line. Only thing I notice when I start to depress the clutch is some kind of noise. Nothing metal, but almost like a rubber seal opening up. It happens ever time I depress the clutch pedal. I also notice that when it does warm up that it is harder to find a gear. Especially reverse. The last thing I would mention is that around 2.5 to 3k rpm is one the clutch seems to start slipping, but it is a gradual thing. Almost like when you slip the clutch on take offs...
Matt, does it make a short sound almost like the occasional disc brake squeal? Is there any free play in your clutch pedal?
If the sound comes high on the pedal and there is no hint of a point where depressing it firms up, it may have been improperly adjusted from day 1 and never allowed to be fully engaged which would cook it and bring about the slip you describe.
 

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My car has the yellow OK also but it is also within the vin break point.Been to the dealer and GM wants to see the car.I think there are more problems than we know.I think the three problems are 1-loose bolts on some,2-clutch slave or masters on some and 3-low fluid level on some causing syncro and bloching ring problems after some miles on some.I think they are trying to get a handle on things now after seeing all these different problems.They really can't afford to just keep throwing parts at it.My problems are similar posted under Grinding gears post.I am supposed to meet with a rep this week or next and I will keep you abreast of what I learn.I hope it is a positive experience or there will be numerous visits for the same problem (if you know were I am going with that).
 

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Flywheel surface taper

Old Goat said:
I have had it told to me that the flywheel on the Manual transmission car has been slightly dished to cushion engagement. If pressed I can probably go find that info again. The point, I guess, is that this is not normal in anything else I have ever owned or driven and sounds to me like a really bad idea, sort of like the TM and Abuse software I have to wrestle with on the A4. It sounds to me like a recipe for frying clutches. Question #1 - No. Question #2 answers Question #3... :(
Not that it helps very much with this problem, but for what it's worth, I remember reading many years ago that some (not all) OE flywheel friction surfaces were machined with a slight taper. The purpose was to reduce chatter on engagement by making the clutch takeup more gradual. For that reason, the article recommended replacing (not refinishing) a damaged flywheel and cautioned about trying to save money by simply refacing it using standard milling machine practices since a perfectly flat surface would be prone to chatter.
 

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Clutch discs

gtofan said:
Not that it helps very much with this problem, but for what it's worth, I remember reading many years ago that some (not all) OE flywheel friction surfaces were machined with a slight taper. The purpose was to reduce chatter on engagement by making the clutch takeup more gradual. For that reason, the article recommended replacing (not refinishing) a damaged flywheel and cautioned about trying to save money by simply refacing it using standard milling machine practices since a perfectly flat surface would be prone to chatter.
That's also the reason the hubs are sprung on the discs, slotted, and the facing material are composites, to prevent chatter on flat flywheels. Whenever I've had a manual I have always replaced the stock cast flywheel, stamped diaphram pressure plate and disc for forged and HD aftermarket units and put on a blowshield. Never re-used an attaching bolt or milled a flywheel either. I got to see a 55 Chevy that had a clutch explosion once without the protections...wasn't pretty. No one hurt, but the car was a sad mess. I'll be investing in a blanket for the auto if I plan on weekending at the track, and a loop. It pays to be safe. The improper torque on the pressure plates on the earlier cars was caught just in time. Some had the bolts backing out on them. Sobering thought. :(
 

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Any clutch behind an LS1 engine since 1997 DOES NOT OPERATE WELL IN EXTREME HIGH TEMPS! We've found this out the hard way. It could be that you could only "hotlap" our cars 3 maybe 4 times at the track, because the clutch would start slipping. You then had to let it cool for a half hour or 45 minutes, then try again.

Anyway, it is a combination of spring clamping force on the pressure plate (which GM sets on the lighter side so as to provide easy clutch actuation), DOT 3 fluid which would boil over due to that high heat and weak throw out bearing springs that did not keep the throwout bearing applying full pressure against the pressure plate.

The only way to truly fix it is to put a hi-performance clutch into these cars and upgrade the hydraulics (although I don't think an upgrade is out yet for the GTO). You will suffer some driveability although it isn't that bad. But it is necessary with the level of power we get from the factory, let alone if you plan to mod it and race it.

I have SPEC stage 3's in both my Camaro and my GTO. I annihilated the factory clutch with less than 100 miles on mine.
 

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Amen

CMNTMXR57 said:
Any clutch behind an LS1 engine since 1997 DOES NOT OPERATE WELL IN EXTREME HIGH TEMPS! We've found this out the hard way. It could be that you could only "hotlap" our cars 3 maybe 4 times at the track, because the clutch would start slipping. You then had to let it cool for a half hour or 45 minutes, then try again.

Anyway, it is a combination of spring clamping force on the pressure plate (which GM sets on the lighter side so as to provide easy clutch actuation), DOT 3 fluid which would boil over due to that high heat and weak throw out bearing springs that did not keep the throwout bearing applying full pressure against the pressure plate.

The only way to truly fix it is to put a hi-performance clutch into these cars and upgrade the hydraulics (although I don't think an upgrade is out yet for the GTO). You will suffer some driveability although it isn't that bad. But it is necessary with the level of power we get from the factory, let alone if you plan to mod it and race it.

I have SPEC stage 3's in both my Camaro and my GTO. I annihilated the factory clutch with less than 100 miles on mine.
I gotta seriously go with CMNT on this. Think of the factory stuff in light of buildings today. It's Code. Code is not the end all, it's just the minimum you can get away with. ALL my rides that were stick got at least a forged steel flywheel, a three finger 3400# Borg & Beck/Long hybrid pressure plate with forged steel plate and hydroformed cover, roller assist, and a serious sprung and slotted disc. The Big Blocks were dual disc floater assemblies. Chatter? Not if you engaged it smoothly and quick. The factory setup will live 50,000 miles if you drive like your parents, and yeah, a LOT less if you don't. This time I got an auto because I no longer feel the need to look like a southpaw field goal kicker on steroids in shorts... :D
 

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I'll buy into this but it is under warranty. Sure you would like a better clutch but if the clutch goes bad and the dealer can't prove abuse they should replace it at no cost.
 

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While in theory I won't disagree with you simply having them replaced under warranty, but is the time and aggravation of having your car in the shop every month for another clutch (which will be replaced free for 3/36k) worth it knowing you'll simply have to go back again for another.

When you spend the hard cash to do it right, you won't need to replace it again except for normal routine wear.

With the LS1, GM Powertain put all their apples (I.E. R&D money) into the fabulous engine, then band aid fixed a basic clutch with what little cash they had left that simply gets the basic job of being a clutch done. Had you wanted a better clutch from the get go, chances are you'd see them skimp elsewhere, namely somewhere on the engine. I'll live with replacing for a better hi-po clutch, thank you very much. :D

You can only slice a pie soo many ways. :D
 

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i don't know about this....

Couple questions in light of CMNT and Old Goat's comments.

1. What is the flywheel/clutch setup on a CTS-V like? Or on a Z06? Both of those cars were tested on, and designed for, the race track. I know they are LS6 but would that setup fit over on the GTO (at least the clutch/flywheel)?

2. If the factory setup can't take 50,000 miles of aggressive driving, that's a SHAME, absolutely disgraceful to GM. My first new car, a 99 SVT Contour, was also the car I learned to drive stick on, and after 55,000 HARD miles the clutch is still in good shape. I am always driving agressively - spinning the wheels, getting wheel hop, power shifting. This isn't to toot Ford's horn, there's many things that are wrong with this car, but I expect at least as long of a clutch life from GM. And actually the clutch on my car was one of the few parts that weren't upgraded by the SVT group in moving from the regular V6 to the H.O. version. Tells you how much safety-margin Ford built into it. (Can't say the same about the rear sway bar setup, steering rack, dash board, shift forks.... ooops, getting off topic here, better stop. :rolleyes: )

Anyways, hopefully these issues are cleared up and I am in a 6M '05 GTO in a few months. :)

Brian
 

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1) They're all the same.

2) The difference is, your SVT Contour wasn't hitting it with a mountain of torque throughout the rpm range and anywhere near the same level of power in general. I'm not putting it down, just making a general observation. I've had many a S-10's with 4 bangers and 6's that had clutches outlast the vehicle itself, but then again, none of them could wrinkle pavement.

Be thankful you don't have an F-Body, they have the same clutch issues and as an added bonus, rear end problems as they use the simple 7 & 5/8ths 10 bolt rear from the S-Series trucks.

GM spends all their money on making great engines, then put clutches and rear ends in as afterthoughts. However, there are many guys I know with M6 LS1's that have 30, 40, and even 50k on a stock clutch, however, they don't have hundreds of passes at the drag strip on stickies, launching the car at 3k+ like some of us.
 

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Matt - any update on your situation?
Dan
 

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Discussion Starter #20
Hi Dan and everyone,

Thanks for all the useful information. So, I gather that I will need a hydraulic upgrade to go along with a hi-po clutch assembly if I decide to go that route? I am really interested to hear if there is a heat soak issue before I sink my own money into a new clutch. I am going to call the dealer today and see if they heard anything from the GM tech center.

The car has been parked in the garage as I am having my driveway paved and didn't want to leave it sitting on the side of the road. I will keep everyone posted.

~Matt
 
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