'70 clutch still broken, help needed to make race

[Grady Clay]

Juan,

Nicely done!

Please post the bearing dimensions. What interference fit? Was the staking necessary or a “just in case?”

I have seen this done with an M8 male Heim and a through tube welded to the arm.


BTW, Did you ever measure the lever arm at the pedal assembly?


Best,
Grady

[randywebb]

my '71 had a nylon cup or maybe I used a different fork in it - tried to forget that project after I finally got it done.

Look in the cup carfully - it will be hard & discolored by now.

Juan - I'm not clear on how the hex head fits into the threaded mount on the case of the tranny (?)

[ckissick]

Juan, I don't know how I missed this thread until today, I try to read everything about a 1970 911, especially about our rare 911 tranny and clutch.

Right away I thought of the pressure plate, because I had the same symptoms about a year ago, and solved it with a new pressure plate. It always ground into 1st and reverse but only after warming up. I did not notice the same damage you had, however. I figured it was worn tynes not releasing the clutch evenly. In any case, I feel like I just solved a Car Talk puzzler. Thanks for sharing valuable info. And thanks to Grady, too. I wish he lived next door to me.

[Grady Clay]

Randy,

I sure hope you have this part in your ’70-’71
transmission and not the original version that
has a 10 mm wrench size nut on a 6 mm thread
and a plastic hemispherical piece. The original
version was very prone to failure.



Does anyone have an image of the early version?

Best,
Grady

[rw7810]

Grady - I'm using the one supplied by our host. I hope it is the updated version, but it looks more "steely" than yours which looks a little rougher as if it has been treated.

[randywebb]

uh....

maybe we aren't talking about the same part of the trans. (?)
I could do up a new thread so it doesn't mess up Juans questions. (??)

I have a stud with a ball on top of it that screws into the trans. case. The clutch fork pivots on that ball (and the nylon cup is in the fork). No idea re thread pitch or what wrench I used 2 years ago... and "plastic hemispherical piece" does not ring any bells either.

[logician]

I should emphasize that this is not my invention. My only contribution was to inherit the part from Thomas, and photograph it for PP. Unfortunately Thomas didn't remember any of the specs on the mod. The fork is now installed in my car, so it is unavailable for additional photographs and measurements. I think the pivot support is based on the parts for the earlier nylon pivot, rather than the newer single piece metal part.

Grady, Sorry, I keep forgetting to measure that lever arm. I'll try to remember next time I visit the shop.

-Juan