ACT clutch won't disengage
 

Ok my Type R has been off the road since 2011 because of an engine failure but I finally got my new engine started yesterday :)

However the JDM STI 6 speed swap with a new ACT SB10-XTSS clutch (+ new streetlite flywheel) is where I'm having problems.

It shifts fine with the engine off but with the car in neutral and engine running I can't get in any gear so the clutch is binding to the flywheel in some way. When starting the car in first gear and with the clutch pressed it doesn't bind enough for it to move the car. Also the clutch operates fairly normal otherwise when driving off as I can tell so the clutch fork is in place as it should. So it's not like it's completely stuck to the flywheel. And yes I used the 6 speed fork.

I don't think it's air in the slave cylinder line either as we spent a long time bleeding it with the slave in the highest position we could get it. And as far as I can tell it seems that the fork is having it's full movement too (is it supposed to touch the casing, it almost sounds like it?). I don't think it will help to adjust the clutch pedal either as it seems to move the rod almost instantly when I press the pedal.

I'm pretty sure we followed every step in the instructions thoroughly, and everything in the correct direction although I can't be 100% on that. But as I said the clutch feels normal when taking off but it doesn't fully disengage so that you can shift gears. I might try do drive it a little bit longer some day to see if it helps but otherwise I guess the gearbox will have to removed again.

Is it a must to use a 6 speed slave cylinder? Right now I'm using my 5 speed original slave as the aftermarket 6 speed didn't function properly and was impossible to bleed for some reason. To me it look like the slave cylinders are pretty much the same in diameter and how far the pin would be pushed out, the difference is mostly in the rear of the cylinders.


Any ideas?

Drove it outside the garage today and tried shifting gears in case it would free up but it didn't. I can get first and reverse in gear but it takes a lot of force so clearly it's spinning.

I took two vids of the clutch fork, I doubt it can go any further and in the second clip you can see it pulling the pressure plate so it should be connected the way it should. But I have no idea what the normal movement should look like. I also tried adjusting the pedal rod without any improvement.

Watch them in full screen
I will try to bleed the slave cylinder again this weekend but I doubt it will help so I guess the gearbox or engine will need to come out again. Perhaps the clutch disc got bent when we installed the engine.

You did put the drive plate in the right way round. There's plenty of travel so don't worry about bleeding for it's not that.

You mean the clutch disc? I'm 99% sure it's installed the right way with the sticker saying transmission side on the ACT disc. Not even sure if it's possible to torque down the pressure plate with the disc the wrong way as the springs on the other side stick out so much. I had a look on my old 5 speed Exedy and it didn't look possible.

And btw I started the car in a slight uphill today and it wasn't any problem driving off so basically the clutch functions nice otherwise. But I guess a bent disc could cause it to stick to the flywheel.

Yes the clutch disc if that's what you want to call it iirc they can go in upside down or back to front on a lightweight flywheel.

Ok maybe it's possible but I'm almost sure we didn't do that. I remember us reading stickers several times about what the correct direction would be. If it would be the wrong way wouldn't it stick much more? With the clutch pressed in, gearbox in first and trying to start the car I would think it would try to move forward with the starter. But it doesn't do that so it's so very little it's sticking.

I more believe that we somehow bent the disc when we installed the engine. We tried to be careful but I can't quite remember everything, we installed the engine in january.

Possibly but they don't usually bend unless you let the gearbox hang down on them. Was the input shaft cleaned and lubricated or there's a very remote chance the spigot bearing has seized and trying to turn the input shaft when the pedal is depressed.

Yes it was cleaned and greased and also I tried moving the clutch disc on the input shaft without issues. It was a new spigot bearing supplied with the ACT clutch, feels unlikely but who knows. I'll try to find a good mechanic who can come and have a look.

I had a look with my inspection camera today and the clutch disc is the right way, I can see the transmission side text.

https://cimg0.ibsrv.net/gimg/www.sco...78d659d9a2.jpg

Drove it some more today but the gears are still hard to get in when standing still, so no improvement at all. Searching this issue it seems other people have had issues with ACT clutches too so I guess I'll have to remove the gearbox or engine again and see what's going on. Possibly buy another clutch because this is out of warranty anyway but not buying ACT again in that case. Hard to tell what the problem is without taking things apart.

Using the stock pressure plate fixed his problem but not clear if it was an installation error or manufacturing https://forums.nasioc.com/forums/sho....php?t=1933464

Looking at your first video again you have plenty of travel but it looks like the last bit could do with going a bit further. Try and move the extra bit with a bar and see will it go into gear. I seen us having to put a longer pin/rod into the slave cylinder to get the travel and I would put your clutch pedal back as it was.

I have the same drivetrain set-up, ACT CLUTCH/JDM six speed, just have the standard flywheel. Standing still with engine running 1st gear is difficult and needs a good deal of arm pressure for it to go in. Once on the move everything is fine and normal but engaging 1st is something I've never experienced before, I had excedy pink box (2) before this. Reverse is less difficult but still a bit of a pull.
Trev

Well my car doesn't run perfectly well with a new engine spec and an Alcatek basemap (for the moment) so it idles at about 1100-1200 rpm making things even more difficult I guess. I'll try to bleed the slave again if there's anything left to bleed. Shifting gears when driving a few hundred meters outside the garage does feel better though.

trevsjwood: Hasn't it got better at all with more miles on the clutch? I would think it would improve with some wear on the clutch.

Well something needs to be done, it doesn't feel good to force the gears in.

It hasn't got any better, I just put up with it as I'm thinking there's going to be issues one way or another with a clutch that holds big power. There'll be some that don't agree.
I agree it's not good to be using any force and the next step for me would be a different clutch.
Trev

the clutch does hold good power and has never slipped when put under pressure but I'd done a 50 mile trip across country and was queuing at a road junction, the approach being quite steep, it started to slip and stank the car out. I don't know why unless it had just got hot for some reason.
Trev

What would be a better alternative to buy in case I have to buy a new clutch? Must be able to take the torque from a 450-480 bhp 2.1 stroker with AVCS heads. And will my ACT streetlite flywheel work with other clutches as well?

Get it pulled apart boss there will be something simple wrong. Did you check the length and travel of your slave cylinder.

I got it a little bit better today by properly bleeding it. It was just a couple of bubbles that came out though. And it's still quite notchy but possible to select gears at least. And when shifting gears driving I don't notice anything wrong at all.

But I noticed from the faulty aftermarket 6 speed slave I bought that the inner diameter of the cylinder was slightly larger than my original 5 speed one. So I think I'll buy a new 6 speed slave but OEM this time in case the slightly larger diameter would help and also being brand new doesn't hurt.

Well your getting somewhere its the travel on the cylinder I would be looking at you may find its more with the 6 speed cylinder.

Stick your camera in and get a visual to see if the friction disc is getting release ok and there is good clearance.

Extreme do a range too, and for only 480hp one of their organic singles would be fine. No need for a twin unless you'd be launching on slicks or something

Yes the slave cylinder was bled removed from the gearbox. The fork was pushed towards the firewall after the engine was installed so the throwout bearing is properly installed to the pressure plate. I have a vid from my inspection cam which shows the movement but I'm at work right now.

I'm using my 5 speed slave at the moment. I did buy a cheap 6 speed slave from ICP (or ebay) but that one I can't get to function properly at all. I have tried installing it two times now. It looks like we get all the air out of it but the pedal doesn't go all the way up and the fork travel is limited also. The original 5 speed it's much easier to bleed and the pedal has it's normal travel.

I have compared the different slaves and the height and how far forward the cylinder extends from the fastening ears look pretty much similar so I don't quite see how a 6 speed slave would have any more travel. But it appears that they are about 1.5mm bigger in the piston so maybe that means more force.

I think I will order a new genuine 6 speed slave cylinder and try. I just don't get why I can't get the new aftermarket slave to work. It's a really simple construction.

A new slave is a waste of money. A smaller diameter slave will give more travel at the fork...that may help if the clutch is not releasing.

But stick a small USB bore scope camera in there to get a visual to see if the plate is getting released correctly and how much clearance if so.

I only have this vid from my inspection camera but it probably doesn't say much (from a few days ago when I still had the 5 speed slave fitted) https://www.youtube.com/watch?v=oL7-lfcKDsw&feature=youtu.be

I removed the pistons from both my slave cylinders and noticed some differences. The internal cylinder depth is pretty much the same. Top one is the original 5 speed, the lower is the 6 speed. The pins are identical. Which would have the longest travel if the spring length etc. even matters?

Could it be that I need to adjust the rod shorter on my clutch pedal in order to get that 6 speed slave cylinder working as it should? I have to pull it up from the floor as it is now.

https://cimg3.ibsrv.net/gimg/www.sco...ca462b6e3e.jpg

I did tell you in a previous post to adjust the pedal back to original place ;) That is a symptom of having to lift the clutch pedal as is a slave cylinder which needs bled they can be a proper pain in the a**e :)

I already adjusted it back to where it was without any difference. But I'll give bleeding the other slave another go, no reason it shouldn't work really. It might take a while before I have enough time to work on the car again but thanks for all the advice :thumb:

mine was grabby too to begin with (as in, couldn't select gears with engine on).

What helped with mine was actually a lot of cursing... basically, I've had my engine and box apart more times than i care to remember trying to get a twin plate exedy to work properly (also not releasing...), and i finally bit the bullet and bought a new ACT clutch, and once it was all fitted etc and i turned the engine on, I had exactly the same symptoms.

So, I'm sat there in the car trying to select any gear, and it's not going anywhere, and eventually i get fed up and sit for a couple of minutes (maybe 2-3) cursing and thinking of other things to try to fix it. By habit, i had the clutch pedal pressed in, and during the cursing session something must have bedded in, because all of a sudden i could select gears etc all fine, and the car seems perfectly drivable now.

I don't know if that's similar to your situation, of course, but maybe just sitting there idling with the clutch pressed in for a bit will allow the clutch plate to wear just that little bit to not be extremely grabby? The only thing I can think of in my situation is that the disc was just a *smidge* too thick, hence not disconnecting properly (but dragging), and that it wore down enough to start disconnecting.

I had this exact problem with one of my clutches.

The problem was caused by torquing the bolts on the clutch cover up incorrectly. Although I had tightened them all to the correct torque my mistake was that I didn't tighten them all up incrementally and in sequence.

So i removed box undid them all and then just tightened them in sequence by 5ft/lb increments until the correct torque was achieved.

This solved my issue.