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Ben's Z

clutch fork won't move

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Ben's Z    10

After installing my engine and trans as a single unit I cannot compress the slave cylinder enough to bolt it back up. The clutch fork won't move worth a ****, even if I put leverage on it with a wrench. I'd rather pull the motor than the transmission at this point. I hate this car.

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Zed Head    542

Does the slave cylinder piston move back and forth in its bore? Maybe it has fallen out and is jammed outside the bore. Let's hope. Take the rubber boot off and take a look.

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Ben's Z    10
Does the slave cylinder piston move back and forth in its bore? Maybe it has fallen out and is jammed outside the bore. Let's hope. Take the rubber boot off and take a look.

It moves fine I can compress by hand.

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Zed Head    542

In this case, that's a bummer.

Does the fork move at all, forward or backward or is it jammed in one spot? You might have jammed the collar somehow on the nose piece in the transmission. It would have happened when you bolted the transmission to the engine. Or maybe the fork is jamming the collar on the nose. See if you can get some wiggle room on the fork then stick a screwdriver in there and try to move the collar. The collar should have room to slide on the nose piece even before it contacts the pressure plate spring fingers.

You might have a tall pressure plate and tall collar but I've not heard of one so tall that the slave wouldn't mount. What pressure plate and collar are you using? Is it possible that the clutch fork is not in the collar slots but sitting on top of the collar? I can almost see the collar in the first picture but it's out of focus in the background.

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Ben's Z    10
In this case, that's a bummer.

Does the fork move at all, forward or backward or is it jammed in one spot? You might have jammed the collar somehow on the nose piece in the transmission. It would have happened when you bolted the transmission to the engine. Or maybe the fork is jamming the collar on the nose. See if you can get some wiggle room on the fork then stick a screwdriver in there and try to move the collar. The collar should have room to slide on the nose piece even before it contacts the pressure plate spring fingers.

You might have a tall pressure plate and tall collar but I've not heard of one so tall that the slave wouldn't mount. What pressure plate and collar are you using? Is it possible that the clutch fork is not in the collar slots but sitting on top of the collar? I can almost see the collar in the first picture but it's out of focus in the background.

I am using my stock 77 trans 5 speed with a exedy stage 1 clutch kit for my 1983 turbo block. Using a 240mm turbo flywheel too.

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EuroDat    241

Ben, I have a couple of ideas.

- Did you have this transmission in the car before your rebuild?

- Does the fork move back and forth at all? Can you see the bearing pushing against the pressure plate?

- Are you using the throw out bearing collar from your 280Z or another one?

- I think the throw out bearing collar comes in two lengths; 24 and 28mm (fork to bearing surface). There might be other lengths. Do you know if you have the correct length collar for the stage 1 clutch your using.

This link shows some of the forks and collar combinations

Transmission2

Chas

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Ben's Z    10
Ben, I have a couple of ideas.

- Did you have this transmission in the car before your rebuild?

- Does the fork move back and forth at all? Can you see the bearing pushing against the pressure plate?

- Are you using the throw out bearing collar from your 280Z or another one?

- I think the throw out bearing collar comes in two lengths; 24 and 28mm (fork to bearing surface). There might be other lengths. Do you know if you have the correct length collar for the stage 1 clutch your using.

This link shows some of the forks and collar combinations

Transmission2

Chas

Yes this is the same transmission from my 77. The donor car (1983 280zx turbo) was an automatic.

The bearing seems fully seated against the pressure plate fingers, but not compressing them.

I was able to put the new bearing on the collar easily. The old collar came off with some light taps with a hammer and socket the same diameter as the collar inside the bearing. No new collar came with the kit.

Bearing looked the same in my old set up as it did with the exedy kit.

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EuroDat    241

You will need a lot of force to press the pressure plate in. You wont do it by hand, maybe with a lever of the clutch fork.

What Im getting at with the collar is the distance between the clutch fork fingers and the bearing surface that pushes the pressure plate. I think your problem might be in a combination of the stage 1 pressure plate and the 280Z collar. If this is the problem, then you will have to remove the tranny:cry:

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Ben's Z    10
You will need a lot of force to press the pressure plate in. You wont do it by hand, maybe with a lever of the clutch fork.

What Im getting at with the collar is the distance between the clutch fork fingers and the bearing surface that pushes the pressure plate. I think your problem might be in a combination of the stage 1 pressure plate and the 280Z collar. If this is the problem, then you will have to remove the tranny:cry:

Which collar would I use?

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ollie    10

Have a read through this thread here: http://www.classiczcars.com/forums/engine-drivetrain-s30/47279-l28-toasting-my-240z-clutch-2.html I am the one who posted last but it sounds to me like you have a slave issue...the slave piston should move back very easily and there is really no way you can move the fork outside the transmisstion by hand, or even with a big pry bar. It does sound like there is an issue with incompatible parts, and I know it sucks but don't screw around too much trying to diagnose this or that when you know in the end that transmisison is coming down. I spent forever bleeding mine to avoid pulling it out, and now I am really good at pulling the transmission out, you will be too. Anyway there are a variety of collars and clutches, the most important thing and this should be a sticky on replacing clutches, is the total distance discussed in that thread. Good luck.

Edited by ollie

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Ben's Z    10

post-21670-1415082288381_thumb.jpg

Ok I leveraged my 18" prybar against the fork and got the slave cylinder installed. Fork is now about half way between front and back as you can see. Pedal is stiffer but this is a stage 1 clutch. "Feels" like clutch is "right there", not sure if I need to adjust or I was able to force that slave cylinder on with the prybar so the clutch is technically engaged? Thoughts?

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beermanpete    27

If you had to force the slave cylinder on in the manner you describe I suspect your clutch is being held in the released position and will not drive the car. You really should take the engine and/or transmission out and find out why it is behaving the way it is.

Edited by beermanpete

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EuroDat    241

Cc

Which collar would I use?

I not sure which collar you now have, but it sounds like you have the longer one. If you open the transmission link in post#8 and scroll down to the clutch forks. You probably have the left one in the right photo. Its 28mm from were the fork fingers sit to the back of the bearing. The right one is 24mm. You could ask the company that supplied the clutch for info on which collar to use.

I think, but not certain of it, that they changed from 280z to 280zx, but that could be onlt the turbo model. It the clutch is for the 280ZX then that could be where your problem is.

Chas

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olzed    10

I had a similar problem, and simply made up a shorter thrust rod for the slave. Worked for me.

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EuroDat    241
I had a similar problem, and simply made up a shorter thrust rod for the slave. Worked for me.

I knew a brickies labourer that had exactly the opposite problem. He had both collars and used the short collar where he needed the long one. To solve the problem he just made a longer rod for the slave cylinder. Only problem was the clutch fork hit the housing before the clutch was completly disengaged. You could only push the clucth pedal 3/4"down. After a test run grinding gears, he had to pull it back out. Talk about bad luck, but he wasnt all that bright...

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Ben's Z    10

I have a 2+2/Turbo throwout bearing collar on the way. Pulling the trans with ZCurves this weekend and reinstalling.

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75mt280z    0

Has anyone figured this out? I had the same problem with the stock clutch. It just stopped working. I started with replacing both cylinders, nothing changed. I then dropped the tranny and installed new pilot bearing, clutch, and throw out bearing, I know I reinstalled the clutch fork correctly, cause I triple checked. Put it back together and it still wouldn't move. What the hell is wrong?:facepalm:

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Mark Maras    284
35 minutes ago, 75mt280z said:

Has anyone figured this out? I had the same problem with the stock clutch. It just stopped working. I started with replacing both cylinders, nothing changed. I then dropped the tranny and installed new pilot bearing, clutch, and throw out bearing, I know I reinstalled the clutch fork correctly, cause I triple checked. Put it back together and it still wouldn't move. What the hell is wrong?:facepalm:

 Define, "stopped working." Won't engage? Won't disengage? Did the throw out bearing slide on the collar easily when you replaced it? Worn collar causing the bearing to bind?

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75mt280z    0
4 minutes ago, Mark Maras said:

 Define, "stopped working." Won't engage? Won't disengage? Did the throw out bearing slide on the collar easily when you replaced it? Worn collar causing the bearing to bind?

Before I had replaced anything, everything had run fine. One day the clutch pedal lost all its pressure and the clutch fork was stuck in the disengaged position. Replaced everything in the clutch system except the fork. And it is still stuck in the same position. Yes when I had the tranny out, the collar and fork and bearing all moved on the input sleeve with ease. 

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Zed Head    542
7 hours ago, 75mt280z said:

Before I had replaced anything, everything had run fine. One day the clutch pedal lost all its pressure and the clutch fork was stuck in the disengaged position. Replaced everything in the clutch system except the fork. And it is still stuck in the same position.

To be sure and clear - you pressed the pedal to the floor, put the transmission in gear, but the car did not move when you released the pedal?  I think that maybe you meant force but said pressure.  Pressure is what's inside the cylinders, force is what pushes against the bottom of your foot when it's on on the clutch pedal.

It's not clear, because there would be no reason to replace the cylinders if the clutch was stuck in the disengaged position.  The clutch engages the engine with the transmission.  It's kind of counterintuitive to interact with the clutch in order to disengage it, so easy to get the words backward..  You engage your foot with the clutch pedal to disenage the engine from the transmission.

Anyway, if it's stuck disengaged that would be a clutch mechanical problem, or a stuck collar, not a hydraulic system problem.

Just trying to figure out what exactly is going on.

Edit - consider also a broken shaft in the transmission.  Maybe the clutch is working fine.

Edited by Zed Head

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Diseazd    321

Sounds to me like you've ordered the right collar.....unless they sent you the wrong clutch. I just installed a 240mm flywheel and an Exedy Stage I comp clutch. I used the 2+2/ turbo collar and she works like a dream (it'll really build up your left leg lol). It's easier to pull the tranny. When you get the new collar, use this test.....if the measurement comes out like in my drawing, you'll be good to go and you'll love the old girl once more. :wub:

IMG_3732.JPG

IMG_3729.JPG

IMG_3730.JPG

Edited by Diseazd

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Zed Head    542

Hey Diseazd 75mt280z appended his post to the end of this long thread.  You might be replying to Ben's Z's 2013 post?  75mt didn't describe his collar.  Nice diagram though.

Edited by Zed Head

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