Clutch goes out after a launch

[randman2011]

I'm normally not a drag strip kind of guy, but I took my 95 Talon AWD for fun on Friday. After my first launch, though, I could not get the car into second. Thinking it was me being stupid, I tried again and couldn't get it into any gear. Once I let the car cool down I could drive it home without issue. Does anyone know what could cause intermittent failure to disengage the clutch (or maybe it's a transmission problem)? I have been told to bleed the clutch system, so I'll remove that fluid reservoir thing on the transmission and bleed it again, but is there something else that I need to look out for?

 

[Zufelt]

how long ago did you put in the clutch and what kind of clutch is it I'm having the same problem that I ran into an act 2600 with the street disc in stock OEM flywheel trying a competition stage 4 6 puck with a fidiza flywheel.

 

[randman2011]

It's kind of a bastard setup since I put the 7 bold from my old Eclipse into my new Talon and chose the parts in the best condition. It is an Exedy clutch disk with a Fidanza pressure plate and a Competition Clutch flywheel. I don't know the models of any of them because I did not buy them. Everything was used but still in pretty good shape. I put it all together about a month ago. The flywheel was purchased new around the same time. The clutch disk has about 30k miles on it over three years. Pressure plate completely unknown.

 

[mercaholik]

It could be the step height is incorrect? Or maybe a mismatch between the p/p and clutch disc? Would the heat from the launch cause just enough thermal expansion that the clutch can't disengage? Not sure if I'm thinking about this right, just trying to think outside the box. You know besides old brake fluid/air in the system but that would be spongey all the time. Not sure if you adjusted your clutch pedal push rod per Jack's trans write up, it's excellent.

 

[randman2011]

It could be the step height is incorrect? Or maybe a mismatch between the p/p and clutch disc? You know besides old brake fluid/air in the system but that would be spongey all the time. Not sure if you adjusted your clutch pedal push rod per Jack's trans write up, it's excellent.

I don't really know what you mean by step height. I didn't even know fully how clutches worked until I took mine apart. The thickness of the clutch disk was almost identical to the old 6 puck that came out and was the same diameter. I have not made any adjustments to the hydraulic setup since it worked fine before the swap and worked fine after the swap. This is the only time that I have noticed anything odd.

Would the heat from the launch cause just enough thermal expansion that the clutch can't disengage? Not sure if I'm thinking about this right, just trying to think outside the box.

I like outside of the box, since that seems to be where all of my problems are. I'm about to start some more threads for those. But as far as heat goes, the car was warm but not hot for all three runs, and by the time I made it to the turn off at the end of the eighth mile, I had regained clutch function. I don't know about any of this, but I feel like that wouldn't be enough time to cool down if overheating were the problem.

 

[mercaholik]

Well then I'm thinking your having a intermittent failure of either your clutch m/c or slave cylinder. Does the pedal feel like it had no power or like isn't pushing far enough?

 

[randman2011]

No power? I don't really remember it feeling any different during all of this, but it has only happened twice for maybe 30 seconds each time. For the record, it does catch right at the floor.

 

[Zufelt]

Just out of curiosity when you launch the car does it feel like the cars being pulled keeping your clutch in the friction zone too long? I'm asking because this is exactly how mine is with my studderbox at 4.5k. It likes to stay there for quite some time eventually putting heat on my clutch not allowing me to shift into second until my rpms drop. Also, does it slip after a launch and is also hard to shift into gears after the initial launch. But when your on a roll and completely floor it it holds and shift fine? Perhaps our problem lies with the clutch? Let me know if your experience is the same. Sorry for the choppy sentences I'm on my mobile phone.

 

[randman2011]

The first launch definitely grabbed really quickly because the engine bogged down and it took forever to get off of the line. The second were much faster launches and the launch limit was increased from 3500 to 4500 RPM. I didn't feel like it was slipping for too long. My datalog shows that it was slipping for 1.3 seconds on my third run.

It has only done this after a hard launch. It does not slip at all during rolling starts or WOT pulls.

 

[Daveregs]

Adjust your clutch Pedal. Willing to bet its too low . I had the same issue with mine. I could be driving normal and have no issue but if I was to get on it. And then hit second the clutch pedal would go straight to the floor and I would have to rep ump it. It sounds like a similar issue your having. I would def check it. It's a 12mm nut behind the pedal.

 

[mercaholik]

Yea I didn't word that right, what I mean is does the pedal effort change? Does the slave move the clutch fork as far as it should? You should def do the clutch pedal adjustment that Jack's trans explains, it's very important to have it properly adjusted.

 

[Daveregs]

Yea I didn't word that right, what I mean is does the pedal effort change? Does the slave move the clutch fork as far as it should? You should def do the clutch pedal adjustment that Jack's trans explains, it's very important to have it properly adjusted.

Yes def. do it.

 

[randman2011]

Haha I will, hopefully tomorrow. Related note: How much fluid does it take to flush/bleed the clutch line? I have part of a can of Super Blue and I don't know if it will be enough.

 

[mercaholik]

I would say at least half of quart, just make sure it's coming out clear. You really might need a little more but I think you will be good.

 

[randman2011]

I would say at least half of quart, just make sure it's coming out clear. You really might need a little more but I think you will be good.

Well I have about a third of a liter. Maybe the capacity will be less with that Fluid Collection Unit removed. On a related note, apparently both the FCU and the clutch restrictor help keep the clutch from engaging at a sporting speed. If slipping for too long is causing this problem, I would think that removing both of those would help.

 

[9091dsmtsi]

I have seen a similar problem turned out to be a broken piece of the clutch disc metal spring retainer became wedged in between the disc and flywheel would not allow clutch to disengage after a while the piece fell out and clutch operation went back to normal. (the guy had already desroyted the 2nd gear syncros). only found it by disassembly. found the piece trapped inside pressure plate dancing around waiting to ruin your day again.