OEM Clutch Assembly Issues/Problems

[TravsSonic]

while we were discussing engine break in, the mention of clutch break in was skimed over. I was asked to make a thread about this, sooooo here is what i've learned about the OEM clutch assembly for the 1.4. This does not apply to the 1.8 as they have a different flywheel and PP, so i have no working knowledge of that assembly. But we can assume its also manufactured by LuK just as the 1.4's is.

Ok. As a dumb dumb, could you explain what I'm looking at here? Why do you think it's not fully engaging? design issue?

We should probably take this over to your clutch thread..

Normally, you do a couple hundred miles of in town driving on a clutch assembly before you ever go WOT. All the starting and stopping allows the clutch to slip slightly every time you take off as well as shift gears. This lets both sides of the discs get all scuffed up and seated well to the flywheel and PP.

This clutch disc had 5500 miles on it when it was removed from the car because it simply would not hold the engine in WOT acceleration.

Thats all that was contacting the flywheel and pressure plate. And thats the only surface area on the discs holding the power transmission from the engine to the gearbox. If an area isn't scuffed, its not contacting, if its not contacting its not helping. You can see on the one picture that the part number is completely visible after 5.5k miles which means none of that area was touching while the clutch was engaged.

Possible reasons...
1) weak/poorly designed PP
2) clutch disc material to hard with to low CoF (Coefficient of Friction)

I personally am swaying heavily towards the weak/poorly designed PP. There is also other issues with this assembly that swing me towards that thought process. The main issue is the grinding of 1st-->2nd shifts above 5k rpm, i'm guessing this PP, while its weak when engaged, its experiencing some issues like some diaphragm clutches at high RPMs and its slightly breaking over at high RPMs while tryin to disengage it. Its not enough to keep itself fully engaged but its enough that its making 1st to 2nd shifts unfriendly and destructive to brass syncros. Since its the syncros job to slow down the assembly, and line up the dogs to drop into place. But if the PP is slightly dragging in a break over then the syncros can't accommodate for the extra load and you get gear grind or completely locked out. The tall gearing between 1st and 2nd exaggerate this issue, which is why it doesn't show in any other gear changes.

This is a VERY well known issue in the cruze forums. One members shop actually received a notice back from GM that they were not to replace the gentleman's syncros as it was a known problem and they are not addressing it atm. That they are to wait till the transmission completely fails from this issue. Then just replace it.

IMO, the issue though is NOT with the transmission. Because I also had this gear grind in my car at 5k+ 1st to 2nd shifts. When i moved to a twin disc assembly the problem and grinding instantly went away. So in my opinion.. this all falls back on the PP. Its simply an over engineered piece of junk. A properly designed PP that works as its suppose to should cure these issues.

just my long winded $0.02

I've also email LuK with the links to my photobucket page with pics of the clutch failure. They haven't responded as of yet.

 

[Masi992]

OK. A few more questions.
1- How much for an aftermarket clutch? Or does only the PP(pressure plate) need to be replaced? What's required to solve the issue?
2- how much to install - Is it a DIY job?
3- Do you think GM will redesign it? Possible safety issue?

 

[TravsSonic]

OK. A few more questions.
1- How much for an aftermarket clutch? Or does only the PP(pressure plate) need to be replaced? What's required to solve the issue?
2- how much to install - Is it a DIY job?
3- Do you think GM will redesign it? Possible safety issue?

1) I think clutch masters single disc stage 1 and stage 2 clutches are in the $500 range. The disc and PP come together, if you replace one you normally replace the other. But you can call them and ask. My assembly is in the $1600 range, as the tester i didn't pay quite that much, but thats what they cost if you just called them up and ordered one like mine. But its also 15 lbs lighter and I wanted it for the direction i plan on taking this car. It just made sense to upgrade it now for what i plan on it doing later.

2) if your competent with tools, its a DIY. I did mine, but i've been tearing apart cars, tractors and trucks all my life because thats just how i was raised. If you don't have at least these tools, don't even attempt it. You need the absolute minimum of
a) 2 jack stands
b) 2 rolling floor jacks (i had one and it was a PITA, 2 would have been nice)
c) 1 cherry picker
d) couple rachet straps to hold the transmission on one side and the engine on the other side of the bay and out of the way during the change
e) a couple torx sockets of a size i can't remember atm
f) socket to take axles out (preferably an impact gun)
g) catch pan for the transmission fluid
h) a trip to fastenal with a one of your main transmission bolts. You have to buy some nice long ones that you can cut the heads off and twist in by hand to use as guides to mount the transaxle back up with. Trust me its easier than man handling it.
i) eye for detail
j) patience
k) understanding that if you break something, you have to replace it and accept that as the trade off for paying someone else to do it. who would probably break it also but not tell you.
l) being organized. Specifically with the bolts that come out of the bell housing and the plastic clips that hold the body work. The bolts are same sizes, but different lengths, you don't want the wrong bolt in wrong hole and strip something because everything is aluminum on this project. And although the plastic clips look the same, they are not. There are 3 very different sizes each has its own hole and each has its own two parts that make it up. That little puzzle took about 1.5 hrs to unravel and made me want to bang my head on a rock. But when it was completely finished I had no left over bolts and thats always a good sign.
m) ft/lb torque wrench


I took it apart in about 6 hours, put it back together in about 10. Needed a extra set of hands when i broke the PP and flywheel loose, when i put them back on and when i actually mounted the transmission back up to the engine. And I won't lie to you, its not a walk in the park. BUT its by far the EASIEST clutch swap i've ever done on a transaxle. No need to drain coolants, or break any fuel lines or A/C lines loose. You just unbolt the engine, drop the exhaust, remove the axles, move it to the side and the transmission to the other side. (talk about over simplified)

You would have to get estimates on the cost for a swap, i didn't even bother. I'm to use to doing my own work.

3) i don't think they will. LuK is the manufacturer, if there is a change it would be with them.

 

[oldertech]

I find that clutch illustration rather disheartening. It's not that I wouldn't be willing to do a job like that, but geeze, I thought the idea of buying a new car was that it would work from the factory for awhile. I'm tired of doing clutches on all the other cars around here, and already have one that I'm going to have to redo.

When we take that first drive at the dealership, is gear-grinding the only sign that this can be a problem? And what conditions make it show off the most? I'm not planning on doing a wideopen throttle when I take that first drive.

 

[TravsSonic]

I find that clutch illustration rather disheartening. It's not that I wouldn't be willing to do a job like that, but geeze, I thought the idea of buying a new car was that it would work from the factory for awhile. I'm tired of doing clutches on all the other cars around here, and already have one that I'm going to have to redo.

When we take that first drive at the dealership, is gear-grinding the only sign that this can be a problem? And what conditions make it show off the most? I'm not planning on doing a wideopen throttle when I take that first drive.

in discussing it on cruze talk, the only time it manifests itself is when you are 5k+ rpm and quickly changing gears from 1st to 2nd (hustling the car). It varies from car to car, but you will either hear a grind as it drops into second or it will grind and then completely lock you out of second gear till the engine drops below 5k. And it might not do it every single time, mine was pretty random and i thought it was just me till i seen others talking about it..

Below 5k, its pretty nice shifting little transmission, you can rev match and up and down shift without a clutch if you want using two fingers. Although its a little more challenging with the dual mass flywheel. Its much much easier with the twin disc.

here is the thread on cruzetalk where it was originally brought up and discussed. If you read down through you'll see the same thing repeated over and over.. 5k+RPM with a 1st to 2nd shift = grind

Grinding during a hard shift to 2nd - Chevy Cruze Forum : Chevrolet Cruze Forums

 

[oldertech]

So, IF that clutch disc had been left in, do you think it eventually would have bedded in like a normal clutch?

 

[RockTheShazbot]

I know your car was tuned so was this partially because of the tune or do you think this would have happened stock too..

 

[TravsSonic]

i really don't know Oldertech.. 5.5k miles and it was barely scuffed. How much longer would i have had to limp it around before the whole face was scuffed? another 5k or 10k miles of it slipping every time i go 3/4 to WOT? I expected to see a fully scuffed disc on both sides that showed signs of being glazed, not a disc that was barely touched. I wish i had an answer for you.. i simply don't. If it had been 500 miles and this happened, i would have just scuffed it and put it back in. But 5.5k miles? something else is going on, because this disc should have been seated LONG before this.

Rock, i don't know that with the stock tune the engine has enough balls to break the clutch loose. If the disc had full contact patch like its suppose to, i don't think that with the tune you could break it loose. The tune just kind of shines the light on a weak part.

I told someone the other day, that if i REALLY wanted to. I could scuff the disc and put the OEM assembly back in it and drive it without the tune till the day i traded off the car. And even if it did slip a little, just back pedal and keep driving. I don't doubt that for a second. Which is why I'm keeping my OEM assembly for the day i do trade it in, i'll just take a couple days before and swap the clutch and flywheel back out, de tune it and trade it in.

But i LOVE the tune, it makes night and day difference in the car. I don't know that I could keep the car if i had to give it up. I would probably have to trade it off and find something else to drive.