Wrong..... now at least

I talked with Spec clutch in person at the Spec clutch meet at there facility in Alabama in March.

Spec clutch has 2 different versions of the Spec clutch for the LNF, one for use with the stock flywheel & dowel pins and one to use with there LW aluminum flywheel & dowel pins.

The difference is in the pressure plate, the Spec clutch setup for the stock flywheel are auto adjusting, just like factory.

Bamaboy can confirm this, he was standing right there when I asked him point blank about there clutch and flywheels.

Spec also alluded to the fact this is why there might be failures, people trying to use the clutch setup made for the aluminum flywheel on the stock flywheel.

Yes, I asked them straight to there face about the clutch failures on the LNF.

Spec guy was nice as hell also, he offered to install my Spec clutch in my HHR SS at his shop at his house for a good price.

 

On the subject of clutch failures there can be many reasons ranging from manufacturing defect, improper design for the application, compatibility issues due to running production changes in intended application, or installer error. For example some examples, I've had very good luck with Clutch Masters clutches over the years but recently had a failure where one of the springs in their sprung hub, six-puck ceramic disc broke on my SRT-4. This was one of their very first kits they built for those cars and in recent years they've modified their discs to reduce the chance the spring can break the retaining cage. Because of this I'd have less apprehension about running one of their discs again but ended up going with an ACT replacement due to their own pressure plate design and replacement steel flywheel that doesn't use a modified OEM modular setup like what I was running with the Clutch Masters.

Also on the same cars, when SPEC released their clutches shortly after the car was introduced they had numerous failures where the disc and/or pressure plate would come apart and quite a few people lost their transaxles due to bell housing damage. A definitive reason was never found but it was suspected to be likely due to defective discs, improper balance, or overheating the stock nodular grey iron pressure plate and flywheel material with the aftermarket disc. For other applications, makes and model you'll find they have a proven track record and make bulletproof clutches.

Sometimes there will be manufacturing limitations or other OEM configurations that affect a clutch's performance. For example, the SVT Focus (of which I've bought two new) came with a small dual-mass LuK clutch setup and some cars developed rattling noise from the flywheel. Ford issued a TSB (technical service bulletin) and revised the flywheel and also made it slightly larger along with the clutch disc and pressure plate for better service life. Fidanza made a lot of the aluminum replacement flywheels that other clutch builders such as Clutch Masters sold early on for that car and it was based on the smaller OEM clutch size in order to reuse the OEM LuK pressure plate. Even with upgraded discs there were still a number of failures across multiple vendors because the clutch size was just too small for higher torque, heavily modified vehicles. Later on most of them started introducing larger flywheels along with bigger discs similar in size to the Ford/LuK TSB replacements and it corrected most of the problems.

There can also be many cases where clutch failures are due to installer or owner error. Especially on organic discs, if the owner doesn't follow the clutch maker's guidelines for break-in it is possible to glaze the disc surface and it will never be able to attain the proper torque holding ability it was designed to have. Sometimes the installer won't surface a flywheel correctly, use the incorrect step (which is the distance between the surface that the pressure plate bolts to and the actual friction material surface) and then have issues with slippage or the clutch not being able to fully release that leads to premature failure. On the Neon SRT-4 I've commonly seen where the installer doesn't properly inspect and replace worn clutch release components that lead to premature disc failure or shifting problems and in other cars where there have been cases in which the installer doesn't bleed the clutch hydraulic system correctly or doesn't torque the pressure plate properly that lead to a new clutch not disengaging correctly, making noise, or failing.


There's always going to be a small number of people who have a failure due to a manufacturing defect. When you move away from OEM to the aftermarket the chances of this occurring can be much greater. Things to look out for when trying to decide on a clutch are repeating cases of failure on certain clutch setups in certain applications that can be traced to an inherent problem with the clutch design. I'd complain bitterly too if I bought an expensive new clutch, installed it right, and it failed. But if I'm the only one or one of a very few that it happened to and the manufacturer made good on a replacement or I screwed up on install that doesn't mean the clutch design itself is bad. Now if multiple people start seeing the exact same mode of failure on a clutch setup you might be a little more cautious before going with a clutch from that company.



There should be a lot of info here on the forums but if you're going to get serious about doing a lot of mechanical work it's a good idea to pick up a copy of the factory shop (service) manual as it will have all the procedures, pictures, torque specs, etc.

If you just want to get an idea of what is involved in swapping a clutch on the Cobalt the GM build books have a lot of good pictures and outline the steps. There's going to be some slight differences for the LNF cars, especially in things like electrical connectors and other items to remove/disconnect to drop the cradle, but take a look at Chapter 5 of the LSJ books.



I haven't had the need to dig around inside my trans yet, but I'd suspect the space in the bell housing could be a limitation. According to Exedy's OE catalog, the LSJ cars specified a 9-3/8" (238 mm) clutch disc (many other aftermarket replacement manufacturers state it as 9-7/16" which may be due to slight variation in discs or rounding error), while the LNF clutches are a larger 9-˝" (240 mm) disc. That may have required a larger pressure plate for the disc and/or the pressure plate was modified to alter clamping force and was physically larger than the LSJ unit. If that caused it to be too big and hit on the internal support ribbing cast into the bell housing they may have needed to reduce the thickness of the flywheel slightly to get it to fit or other small changes.

 

Some of the bolts are a bitch to find... other than that its really not that hard, especially if you have a friend helping. Between myself and my neighbor, we knocked it out in around 4.5-5 hours (this was a transmission change as well). Next time we do it it will be much faster, a lot of that time was lost looking for the bolt thats hidden behind the starter and some other bolt I cant remember.

Just get the car up as high as you can get it, it makes it much easier.


I went with the Excedy Hyper-single. Expensive as all get out, but so far worth it. It does not slip at all on slightly modified cars like mine. Yet to see how it does when I finish the engine build, turbo swap, and new transmission (goal: middle of next year on the turbo and tranny, engine now).

 

Awesome notes! I'll keep these things in mind and definitely go get a 36mm DEEP socket! It always sucks when you're half way through a project under your car and find out you need to go to the store to get a tool.

 

Makes sense. Way back when I got mine 15 mos ago there was only one option for the LNF in the way of the PP setup afaik. I had originally ordered it for using the stock flywheel and having to machine out the dowel holes, changed my mind, called the SPEC rep and he spent 10 mins while on the phone cross checking his info and assured me the setup I ordered would work on the LW flywheel, just don't use the dowel pins they sent with the clutch.

Perhaps my inquiries led to further development? IDK. I was running a sprung Stage 2+ disk, PP & LW flywheel. I initially had dragging issues, but that was caused by it being airbound. Thanks for the info.

 

Thanks for the info guys. I'm reading chapter 5 right now. I have a good amount of tools and a garage, so I think I can do this with the right documentation.

 

HHR, where did you get the jack for the cradle? Did you rent one? From where? Thanks.

 

I used 2 jacks, balancing act my freind.

Taking it down was easy, putting it up was a bitch.

 

This is what I was afraid of. You can't really manipulate it much when it's on jacks. I'm still doing this when it comes time, though.

 

I bought the engine cradle (they call it an engine support bar) from Harbor Freight for $70. I bought one because i'm always doing work on mustangs and it could come in handy.

 

I had an actual transmission jack for the transmission my self, but you could take the transmission in and out without one.

Its not very heavy.

 

Thanks! I never thought about HF. I see the red bar. I'm gonna go get that very soon.

 

SSlobalt, did you get the clutch in?

 

I'm not quite there yet. It'll be another 6 months or so before I need it. I'm just getting prepared. Thanks, HHR!

 

wait what? I missed this post? Why did his throw out bearing fail?

 

idk but i know he said he had issues with it since day one so it could have been bad part or install it was barely even broken in so idk, i haven't had any issues with mine

 

He said it started making noises after about 500 miles and has gotten worse. IMO, if it was a bad install it wouldn't have been right when he pulled out the shop.....but i'm not an expert.
The new TOB going bad is just dumb luck, but like anything else it can be bad while brand new in the box, could go bad in hours or last years. Ya never know

 

When I had my KY clutch installed, the FW still looked like new. No marks or deposits, so we decided to leave it alone and not resurface. Clutch feels great and pedal pressure is like stock. I'm very happy with it at this point.