911 clutch fork (Grady, Tyson, others?)

[DByers]

Okay so I have finally got the engine and the trans ( 911.301.101.0R) apart and it looks like the problem is the #5 in the following diagram and how it now fits in #2 in the diagram.

There is so much slop in this area that the fork can touch every side (N-S-W-E) of the trans opening with out problem. The bolt #5 is firmly in place. So, do I replace with OEM parts? I was reading this THREAD and it looks like Juan may have a great solution for this problem. As far as I know, these parts are original to the trans and car. The trans was gone through 5 years ago by a reputable shop and these items were not replaced.
So how do I fix this so I can drive my Stay Puff again?
TIA
Sorry, need to add - trans is from my 71 911T targa

[john walker's workshop]

the fork will be sloppy until it is engaged with the t/o bearing and you have turned the bearing 90° to get the fork tips locked under the bearing wings. then you will see much less slop. if the flywheel was machined, you will need another flat washer under the normal washer to keep everything in it's proper release goemetry. machining the flywheel moves the clutch closer to the engine, so the fork needs to move too, or there can be release issues. washer thickness relates to how much was machined off. hard to tell sometimes.

[Tyson Schmidt]

Good advice.

Dan, what I was telling you on the phone is that part #4 holds the release fork engaged on the release bearing with spring tension. There are little indentions that the fork fingers stay in so long as the spring (#4) holds them together.

I think Patrick Motorsports makes a really strong version of the pivot (#5), that'd be a great idea to change out while it's apart.

[DByers]

Thanks John & Tyson. The only thing replaced since my recent problems were the clutch disk and clutch cable. The PP and flywheel were inspected and givin a clean bill of health. So now instead of a slipping clutch ( that finally ended in a stuck in gear problem) I have a trans that shifts fine for about a dozen shifts or so then ends up baulking a few more shifts then it gets stuck in gear. I get home and find the fork has become misaligned and it starts all over again once I realign the fork ( I have become real good at it from underneath the car now ) The other thing is my #3 washer is cupped, not flat and the order of progression was #4-#3-#2-#5 unlike the picture where the washer is first in line. Perhaps this is the problem? I mean the clutch was only 5 years old from when the tranny was redone and lasted maybe 20k miles. It was definalty done when I pulled it out (Ingo said it was paper thin). Perhaps this clutch fork issue lead to a premature failure? I am just trying to make sure when I button this back up and put the engine & trans back in the car it works like it should. Are there any measurements I can take that would help?
Thanks again

Tyson, Ingo said you may have plans to be up this way in the near future. Perhaps I could bribe you to come by and take a look?

[DByers]

Randy, I linked to that thread in the first post and it has been helpfull. I am wondering though about the modification Juan has on his fork and how it was done.
Here are some pics of my fork, pivot, spring and washer


Here in this last pic you can see how the washer is not flat.


I dont have the experience of seeing alot or actually any other 911 trans besides this one (mine), so I dont know if these parts are correct and in order. I dont trust any one local as they always look at me crossed eye when I say I have a 71T. I need a home visit from some one who knows and maybe even cares about these older cars.

[Grady Clay]

When you say you have to re-align the fork do you mean
you have to rotate the clutch release bearing and get the
fork back in the detents?

If so, the first thing I would try is to bend the finger spring
so it has more pressure on the fork. If you bend it a little
too far that won’t hurt anything. The order of locating the
finger spring is the spring against the casting, then the
tapered washer. The critical issue is for the spring to have
proper force on the arm.

Here is the finger spring (red). The original diagram doesn't
show the finger spring.

"
"
© Dr. –Ing. h.c. F. Porsche A.G.

Note that the above image has the early pivot with the
M6 nut (10 mm wrench size). If anyone has that pivot
you should install the Factory update at your first
opportunity.



This set of intricate pieces for a 2.2 Type 911 transmission
requires a lot more maintenance than any other
clutch Porsche has used. On the other hand this set-up
allows the larger 225 mm clutch to be used in a 901/911/914
transmission.

Best,
Grady

[DByers]

Thanks Grady,
Yes, by realign I mean I have to turn/rotate the release bearing. The pivot bolt head takes a 13mm wrench not a 10mm. I will play with the tension/bend in the spring with the engine and tranny on the bench to get it correct. Then I will install everything back in the car. I will order a new spring, washer & bolt just in case. During this time I have been able to tackle my speedo drive leak (fixed) and clean up the engine bay. I will also be replacing my trans mount with the WeVO System. I am becoming much more familiar with my car after 20 years of ownership so all is not lost.

[randywebb]

1. "the early pivot with the M6 nut (10 mm wrench size)."
* * *
2. "On the other hand this set-up allows the larger 225 mm clutch to be used in a 901/911/914 transmission."

Grady, I broke your quote above into two pieces:
In [1] is that early pivot the one with the ball on the end of it?

In [2] does "this setup" refer to the ball based one? And does that mean you can't upgrade as you stated above and still use the the larger 225 mm clutch in a 901/911/914 transmission? (which is what I am doing).

[Grady Clay]

Dan,

I can sense the fun you are having. It is the addressing
of these “problems” and being able to fix them is part of
what Porsche is all about. I drive a 911 with a mental
picture of all the little systems, bits & peaces in my mind.
I used to do that at 215 MPH while concentrating on the
driving and racing. Sorta like partitioning a hard drive
without diminishing its performance. Hehe.



Some things that would be useful to measure are some
installed dimensions.

First is the distance between the arms of the fork “Z”.
Another is the thickness of the part that contacts the
release bearing (not shown). That is a wear area.

"
"

Note where someone has ground clearance to the corner
of the pressure plate in the arm (brown arrow). I would
clean that up and polish it to eliminate grinding groves.

Is your pivot (yellow arrow) Factory, OEM or aftermarket?
It appears different from the one I have.
What is the thickenss of your tapered washer and finger spring?
Use a micrometer (±0.01 mm).




Another is to devise a fixture to pull the fork against the
ball in situ and measure dimensions “X” and “Y”
when the arm is resting at its normal (no clutch operation)
angle.
IMG ClutchFork70_71&Parts03


© Dr. –Ing. h.c. F. Porsche A.G.

None of there are specified in workshop manuals and
are invaluable troubleshooting this system.

Best,
Grady

[DByers]

Grady and others,
I will spend some time in the garage this week and measure any and all things that people would like me to measure. Ingo S. is going to make his way over sometime this week for a beer and we can work on the measuring the "X" & "Y" in your diagram. As to the originality of the parts, all I can say is I have owned this car since 85 and this year is the first year I have had to pull the engine/tranny (3rd time is a charm right?). The tranny and engine were worked on 5 years ago but not by me (before I heard of Pelican and Rennlist). The tranny was gone through and from my paper work these items were not replaced. I am guessing by the looks that #4 is an OEM piece, not factroy, like the one our host sells. I am checking with Patrick Motor Sports as to a reinforced pivot and maybe stronger spring.
Grady, do you still need measurements from the pedal cluster area? I recall you were looking for something on a previous thread.
Randy, I have subscribed to the new thread you started and hopefully some good tips will be there soon so I can use them in my tranny.

Grady, based on your post below my pivot is the factory update as it has a 13mm head. Dont know when it was installed though.

[Grady Clay]

Randy,

I edited the above post so I hope that clarifies things.

I wasn’t talking about these subtle differences within
the 2.2 pull-type set-up but comparing the 2.2 pull-type
set-up with its 225 mm clutch to the earlier push-type
215 mm clutch.
Sorry for the confusion.


There is the early pivot (10 mm wrench on a M6 nut) and
the Factory up-date pivot (13 mm wrench on the pivot
itself.) If you have an early pivot it will also have a white
plastic hemispherical part that mates with the arm socket.
It would be great if someone could post good images of
the early set of parts. They are shown diagrammatically
on other threads.


What issues are you facing with some conversion?

Best,
Grady

[randywebb]

I'm not having any issues with a conversion - the conversion I did works (911 trans into '73 car with 225mm plate on a 3.2L motor) -- I just want to be sure it will last...

I have pics of the ballhead pivot for the clutch fork. But, the bbs won't let me upload pics > 100k and I gave up on trying to cut the pic down after several tries.

[Grady Clay]

Randy,

Download this freeware:
irfanview@gmx.net

It is wonderful for re-sizing images.

Go to:

Open (browse and find your stored image)
Images
Resize/resample
Best to fit desktop
Save (to wherever)

Works great, converts my bit images to jpg, it has lots of other features, is free, and was recommended to me by another Pelican. Minimal clicks for what it does.

Best,
Grady

[randywebb]

thx - but I have it and used it.... may try later when I have more time to futz w/stuff