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Just installed a rebuilt transaxle in my '72. Ground the flywheel and installed a new Weber centerforce clutch from Pantera Performance. The clutch works very smooth, but there is a slight drag on the RPMs when you depress it all the way. Also, I had to adjust the slave cylinder pushrod to the shortest possible size, or it will grind. This surprised me because I expected a longer rod to release the clutch sooner, or more completely.
There is still a slight clunk shifting up into 2nd gear. No clunk downshifting to 2nd. Since 2nd was the bad gear in the rebuild, I'd like to get this right!
I have .108 free between the adjusting screw and stop plate at the slave.
I also fiddled with the master cylinder pedal adjustment under the dash. The clutch is only disengaged when the clutch pedal is all the way to the floor. I thought if I lengthened the master pushrod I would get disengagement sooner, but all the adjusting seemed to do was bring the pedal out farther while still requiring the pedal to be mashed to the floor.
How long should these pushrods be if things are operating properly?
Would a new long throw slave cylinder help the disengagement? Would it affect the pedal position?
I have been told that there is an updated clutch master cylinder actuation linkage that will change the disengagement position of the pedal. Has anyone used this kit? Is it worth $350??
Any and all experiences and help will be appreciated.
Thanks, Mooso.
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What's the gap between the clutch plate and the
flywheel when the pedal is all the way in at the adjustment when it doesn't grind ?

I replaced my clutch and then the slave about 2 months later.

When I replaced the slave on mine, it made a world of difference but took some time to get dialed in right. I had to re-adjust just about everything not to mention bleed the system serveral times.
I replaced the slave just 3 weeks ago with a long throw version. With the old slave, first & reverse were difficult to get into and would often grind even with the clutch to the floor.

Drained the old black gungy brake fluid from it, adjusted the slave once to remove any freeplay & now all gears shift smoothly.

So I would suggest you start with the cheaper choise of upgrades (a long throw slave) to see if that cures your problem.
Cos, will I be able to measure the clutch plate/flywheel space through the inspection hole in the bell housing...or should I have done this before final assembly?
While the car was sitting, the end seal of the slave migrated out of the slave body and most of the clutch fluid was lost. Maybe I need to work on bleeding the fluid more thoroughly.
It's sounding like the long throw slave may be a good investment.
Any more experiences?
Thanks, Mooso.
Mooso,
Yes, you check for the free play through the sight opening on the top left, drivers side of the ZF bell housing.

This is something that's done after everything is back together.

You should check the disengagement distance at the flywheel. In a Pantera, this is done with a feeler gauge thru the bellhousing access hole. With the clutch fully depressed, you should be able to insert a 0.040" feeler gauge between the disc & flywheel. This means 0.020" clearance on both sides of the disc: barely-enough. If not, you have too much slop in your system and no amount of adjustment on the slave cylinder will help. Less than 0.040" means that the clutch drags at each shift, wearing the synchros in the ZF trans. ZF synchros are all-steel so when they wear out, they take the mating gear with them, so it behooves everyone to adjust for maximum disengagement, regardless of 'freeplay'. (Jack's quote)

I got my new clutch slave cylinder from PI International, for if I remember correctly about 100.00 and it's a very nice piece. Call Jerry at PI, he's a great guy and doesn't mind questions and helping you get through the installation of it. He taught me a lot.

Absolutley on the bleeding. If there is ANY air in the system, your not going to disengage completely. Which will cause the dragging of the clutch plate and grinding of the gears. A real BIG NO NO.

Tons of experiences, the longer you own the car, work on it and stay involved on this website, the more you learn. Part of the fun of owning the cars.

Recently I thought I had second gear problem, popping out while driving in second gear. So I figure it was the second gear itself or the synro ring. But it was something that just started overnight. So I started thinking what I had done recently that could effect the ZF. It appears now that it turned out to be the shifter interior boot that I had just replaced. It was new, very tight and was putting just enough pressure on the gearshift lever in second to push it out of gear. I removed the boot and didn't have the problem anymore. So I modified the boot to releive the pressure and it solved the problem, for now anyway. Something so simple caused weeks of worry and hassle.

There is a bunch of adjustments with the shifter, linkage, master and plate to flywheel. They all have to be just right for everything to work perfectly. Check all the linkage, make sure everything is clean and greased, bleed the system several times, check all adjustments and try it again and see what happens.

Hope this helps.
Geez...I hope I can explain this clearly enough.
When you depress and release the clutch pedal, you can see the fiber sides of the clutch plate (one fiber disk on the flywheel...one fiber disk on the pressure plate) compress and expand. Its as if they are not firmly bonded back to back, but are slightly "squishy" in the center. If I use a screwdriver to compress the fiber disks together, I can get a .040 feeler guage to slide right in. If I do not compress the "squishiness" out of the clutch plate, I can barely get a .020 guage between the clutch plate and the flywheel.
I expected the clutch plate to be a fiber disk, a metal disk, and another fiber disk, bonded solidly together. I did not expect the center of this fiber sandwich to expand and contract with pressure.
I assume this friction plate is made properly and I am just not knowledgable enough to know better...but if I need .040 absolute clearance between this plate and the flywheel, then I am way shy of that.
Mooso.
That sounds like your problem then. Your not getting enough dis-engagement so the flywheel never fully releases from the pressure plate.
Reading back on your first post, you said you adjusted the clutch pedal under the dash. The adjustment you did may be not depressing it far enough now. Hard to tell with seeing it.

I noticed when I replace my clutch, it was a little stiff too, but it worked itself in in a few miles. But I had no problem getting the .40 right from the beginning with just slave cyl. adjustments.

How old is the Master Cyl ?

Also check your Trunion bearing and make sure it's greased and not binding.

E-mail me at cozland@cox.net and I will send you my phone number to call me.
It will be easier.
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