2 hours ago, Sailor Bob said:

I seem to have exactly the same issue

That's not good.

This thread might be interesting.

 

I read the full 5 page thread. It seems to me the clutch kits from zsource may be the culprit issue. Too late and messed up for a return. Any idea where is can source the correct clutch assembly to use original gear/sleeve? Ild be satisfied to pay the additional cost to buy another as long as it works.

“Someone” totally has to design a variable length throwout bearing collar. Then buy any clutch you like and adjust the length of the collar to get the “rule of 92mm” total height. Enough of these struggles already.

 

One thing that I had forgotten about that I've seen on other cars, is the height of the pivot ball.  We really should have that pivot ball height as a variable in the whole "92 mm" solution.  If the pivot ball is short that screws up the whole equation.  The washer under the pivot would be a factor too.  I seem to recall a lock washer.

Here are are some examples.  I wonder if there are variations in the Nissan transmissions.

https://www.speedwaymotors.com/Adjustable-GM-Bellhousing-Clutch-Fork-Pivot,712.html?sku=5503855&utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gclid=CjwKCAiAm-2BBhANEiwAe7eyFG8N4a_JIC8cKxYJpinHOb48MAHr5-x6wb0xJJmKFLVknBKHIUyi_hoCgNgQAvD_BwE

https://www.jegs.com/i/Hays/490/84-116/10002/-1?gclid=CjwKCAiAm-2BBhANEiwAe7eyFNypj6L5trSXEoFY_4KFgt8v37pZIJ7MPtWAlID2eYNIsuk80E8oExoCaGMQAvD_BwE

Edited February 28, 20214 yr by Zed Head

Part #7 shows two numbers, but the first is probably the monkey-motion transmission.

http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/clutch

And the lock washer, #8.

http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/clutch/8

Edited February 28, 20214 yr by Zed Head

19 hours ago, Sailor Bob said:

I read the full 5 page thread. It seems to me the clutch kits from zsource may be the culprit issue.

Sorry to hear you're having the same problem @Sailor Bob, but at least neither one of us is crazy (or we both are).  I had to re-read the thread to remember, but it seems to me like the issue isn't actually the pressure plate or the collar, as I was getting the proper 92mm stackup.  The problem seemed to be that that my pivot ball was too short.  I'm not sure how it's possible, as @240dkw's pivot measures the same on the bench as mine but a few mm longer when installed.  Some kind of local space-time distortion is the best I can figure (or measurement error on my part, whichever makes more sense).

 

Adding an extra 4mm of washers under that pivot ball brought the distance from the tip of the ball to the front face of my bellhousing to 105mm (@240dkw's measured 103mm).  The transmission is now installed and I've been driving the car every chance I get. The clutch feels perfect.  I'm hopeful you can solve the mystery, but if you get tired I recommend just slapping two 2mm washers under that pivot and see if that fixes it for you.

Edited March 1, 20214 yr by rcv

8 minutes ago, rcv said:

Adding an extra 4mm of washers under that pivot ball brought the distance from the tip of the ball to the front face of my bellhousing to 105mm (@240dkw's measured 103mm).  The transmission is now installed and I've been driving the car every chance I get. The clutch feels perfect.  I'm hopeful you can solve the mystery, but if you get tired I recommend just slapping two 2mm washers under that pivot and see if that fixes it for you.

Thanks for the reminder, I had forgotten how you solved the problem (state-dependent memory maybe).  The proper measurement is already here in this thread.

Well that seems to be a simple solution. Still heavy winter here so i still have a couple of months to get it sorted out. Thats only one issue on the way to roadworthy im sure. 
thanks for the helpful suggestions 

Sure thing, let me know how it works out.  I'm still academically interested in what the root cause is here but so far my curiosity hasn't been as strong as my desire to drive my car. 

On 2/28/2021 at 1:10 PM, Sailor Bob said:

I read the full 5 page thread. It seems to me the clutch kits from zsource may be the culprit issue. Too late and messed up for a return. Any idea where is can source the correct clutch assembly to use original gear/sleeve? Ild be satisfied to pay the additional cost to buy another as long as it works.

Looks like you can get one at Napa. 

https://www.napacanada.com/en/p/NCF1106029?partTypeName=Clutch+Pack&impressionRank=1&keywordInput=clutch

$303 ... yikes. Although exchange on the dollar and shipping from California to nfld ...

Rockauto has a couple of choices at a better price.