Clutch Problem

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E. Neil Zuchowski
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Clutch Problem

#1 Post by E. Neil Zuchowski »

Working on a 356C that I purchased in boxes. Car is about 95% finished. Engine is a 912 that I rebuilt with a new 200mm flywheel, clutch and throw out bearing. When I depress the clutch pedal, there is no discernable change in pressure. Clutch cable is functioning, throw out bearing lever is moving (about 2 inches) and pedal free play is about an inch. It appears to me that the clutch is not dis-engaging as will not shift into gear while running. I am new to Porsche's but not to rebuilding cars or installing clutches. I am hoping that someone has some great ideas on how I goofed up. Hate to pull the engine again, but it looks like that may be necessary. Thanks in advance. Neil

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Martin Benade
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Re: Clutch Problem

#2 Post by Martin Benade »

Do you know what throw out bearing is installed? Does it really go with the pressure plate that you are using? When you say no pressure change, do you mean that the pedal moves too freely, not compressing the pressure plate? Has it been together long enough that the clutch disk could be stuck to the flywheel?
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Vic Skirmants
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Re: Clutch Problem

#3 Post by Vic Skirmants »

There have been instances of the clutch arm breaking free of the shaft. If it is intact, try moving the clutch pedal stop up.

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Doug McDonnell
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Re: Clutch Problem

#4 Post by Doug McDonnell »

I hate to ask but new 912 flywheel or new 356 flywheel? And part number/where did you buy it?
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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Thomas Sottile
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Re: Clutch Problem

#5 Post by Thomas Sottile »

How long has the clutch been sitting in the car maybe it is stuck to the flywheel. not uncommon
Last edited by Thomas Sottile on Wed May 01, 2019 7:30 pm, edited 1 time in total.

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Thomas Sottile
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Re: Clutch Problem

#6 Post by Thomas Sottile »

If the clutch has been sitting in the car a while it may be just stuck to the flywheel

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Re: Clutch Problem

#7 Post by Norm Miller »

What is the distance from the T/O bearing pivot to the face of the T/O brg?
Sounds like you have a thin brg and need the fat one.
 

E. Neil Zuchowski
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Re: Clutch Problem

#8 Post by E. Neil Zuchowski »

Thanks for all the ideas. It is a 356 flywheel and I bought what was advertised as the correct bearing. But it could be wrong. The clutch disk has been in about 3 months. The clutch pedal stops just short of the stop. I can move the pedal easily with my hand and there is no change in pressure as I push. Seems like it isn't engaging the pressure plate. Your ideas gave me the starting points I needed. Thanks.

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Paul Lima
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Re: Clutch Problem

#9 Post by Paul Lima »

Two possibilities from personal experience: clutch disk is stuck to the flywheel or, the arm to which the clutch cable attaches has broken loose from the tube that moves the throw out bearing. In the latter case, all looks well from the outside, but the t.o. bearing isn't moving at all.

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Vic Skirmants
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Re: Clutch Problem

#10 Post by Vic Skirmants »

" I can move the pedal easily with my hand and there is no change in pressure as I push."
Maybe you just need to take up the freeplay.

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Paul Ahnell
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Re: Clutch Problem

#11 Post by Paul Ahnell »

I'm with Paul Lima and speak from experience on this one. Check the roll pins that secure the throwout bearing fork to the transmission cross shaft. I had mine shear out of the blue in the middle of nowhere and it acted just as you described.
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Vic Skirmants
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Re: Clutch Problem

#12 Post by Vic Skirmants »

Good post, Paul. I had forgotten that. It happened to me 53 years ago.

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Thomas Sottile
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Re: Clutch Problem

#13 Post by Thomas Sottile »

to check if you clutch plate is stuck to the flywheel just jack the rear wheels off the ground in a safe way, start the car in gear second will do, and hit the gas and then the brake do this a few times and it should brake loose. be careful.

E. Neil Zuchowski
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Re: Clutch Problem

#14 Post by E. Neil Zuchowski »

Pulled the engine this afternoon. Everything looked good until I measured the distance from the T/O bearing to the transmission flange. Its suppose to be 1 31/32 and if I measured right, my is 2 1/2 inches. As several said I must have the wrong bearing. Part number is 901-116-081-01 (RC-7). This bearing is identical to the one that I got with the car that was only marked 4301. The car came with a 180mm flywheel which I changed to 200mm when I increased the HP. Any ideas on the correct bearing. I really appreciate all your help. Neil

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Doug McDonnell
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Re: Clutch Problem

#15 Post by Doug McDonnell »

That is the correct TO bearing for a stock C/SC, Something has been modified or else assembled incorrectly. Maybe you have the conversion for use of 911 TO bearing? https://porsche356registry.org/article/29
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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