Question about Clutch Fork throw???

[auzziez]

I realize that this is one of those posts that is probably going to generate more questions than answers.

I have an S30 with a 5-speed transmission. What I am trying to determine is the distance that the Clutch fork should move when the clutch is pushed in. I don't have any info on the tranny other than from the pictures that I am attaching here.

The problem that I am having is that the clutch is not disengaging the transmission. I measure the throw on the fork and it only moves 11mm, which looks to be only about have the distance that it could travel.

I understand that there are numbers on the top of the bell housing that would tell me the exact tranny model, but I want to hold off on dropping, unless it is absolutely necessary.

Any help would be appreciated.

Edited September 17, 2012 by auzziez
adjust pics

[Zed Head]

Blue just gave a number in this thread - http://www.classiczcars.com/forums/showthread.php?t=47300&p=410213#post410213

The numbers on the bell housing won't tell you much, and won't have much to do with how your clutch works. It's the combination of pressure plate and throwout bearing collar that matters. Tell some details about what clutch package you started with and any changes you made when you put the new transmission in.

The transmission looks like a 77-79 "early" "wide ratio" 5 speed, by the way.

I see that you have the adjustable rod from the slave cylinder. Have you tried extending it yet?

Edited September 17, 2012 by Zed Head

[Reverend]

Im very interested in this topic as im about to change 77 5 speed to my -72 240z. I have Exedy (made in Japan) clutch kit. I noticed that the 77 tranny has fill plug on the other side.

[Carl Beck]

The problem that I am having is that the clutch is not disengaging the transmission. I measure the throw on the fork and it only moves 11mm, which looks to be only about have the distance that it could travel.

When is it not disengaging? If it is at start up - that you can't put it in gear - then the clutch may be fine - but the clutch disk is rusted to the flywheel - that happens in Florida when the car isn't driven for a few months.

If the car starts - you can put it in gear and drive it - but the gears grind when you shift - then it could be a problem with the clutch master or slave.

That is a 77-79 5spd - and it was professionally rebuilt a few months before you bought it. {John Williams in Atlanta}.

FWIW,

Carl B.

[auzziez]

thanks for the replies so far, the real problem that I am having is with the car in gear and clutch pressed in the car will lurchforward when I turn the key. if I take the car out of gear, it will start no problem, but won't shift into gear without grinding. the clutch fork will move 11 millimeters so there's pressure in the hydraulic system. any ideas on how best to troubleshoot this, thoughts?

Edited September 17, 2012 by auzziez

[Zed Head]

Do you have a good idea of how the clutch works? You haven't responded to Posts 2 and 4 and you're asking the same question over again.

[auzziez]

I thought I answered post 4 just a moment ago, and no I have not tried extending the adjustable link

[Zed Head]

You didn't give any details about the clutch parts that are in the car. Are they the 240Z parts or did you install a 280Z clutch to match the 280Z transmission?

Actually, extending the rod probably won't help. If the rod was too short, the slave cylinder piston would just pop put, unless the rubber boot is retracting it when you release pressure. I would loosen the rod adjustment nuts, push the rod back in to the slave cylinder, and re-tighten.

The other possibility is your pressure plate and collar combination.

Edited...

Edited September 17, 2012 by Zed Head

[auzziez]

You didn't give any details about the clutch parts that are in the car. Are they the 240Z parts or did you install a 280Z clutch to match the 280Z transmission?

Actually, extending the rod probably won't help. If the rod was too short, the slave cylinder piston would just pop put, unless the rubber boot is retracting it when you release pressure. I would loosen the rod adjustment nuts, push the rod back in to the slave cylinder, and re-tighten.

The other possibility is your pressure plate and collar combination.

Edited...

Got It! I wish I could provide that information, unfortunately, the tranny/clutch combination were in the car when I bought it, and the tranny has never been off of the car.

I'm going to start with the obvious work that I feel comfortable doing myself. If it comes to dropping the tranny, I'll have to take it to a really good tranny shop nearby that has worked on my Supra Turbo.

I'll refer to Blue's thread since that looks like very relevant information.

[Zed Head]

I went back to your first post and realized it's not clear if the clutch has ever worked. I kind of assumed that you had put the 5 speed in and were having problems.

The first thing that I would do is remove the rubber boot on the slave cylinder and see if there is brake fluid inside (brake fluid is used for the clutch hydraulics). If there's fluid inside, you need a new slave cylinder. It's common to get some, but not all, of the stroke when the cylinder starts to go bad.

[Carl Beck]

thanks for the replies so far, the real problem that I am having is with the car in gear and clutch pressed in the car will lurchforward when I turn the key. if I take the car out of gear, it will start no problem, but won't shift into gear without grinding. the clutch fork will move 11 millimeters so there's pressure in the hydraulic system. any ideas on how best to troubleshoot this, thoughts?

Sound like the clutch disk is rusted to the flywheel. We had a discussion here a few weeks back about how to break it free.

You have to roll the car out on a street with no real traffic. Start the car and let it warm up so it is running fine, then shut it down, then put it in 1st gear. You have to get the car rolling in gear - by starting it in gear and letting it roll forward with a little throttle at about 20mph. Then you have to stop the rear wheels from turning while at the same time you hold the clutch pedal to the floor and apply more throttle. You stop the rear wheels from turning by using the E-Brake. You yank it up HARD. You may have to repeat that process a few times.

FWIW,

Carl B.

[Reverend]

Siding this conversation: does the -72 240z clutch slave cylinder work on -77 5 speed?