Slipping clutch

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Anthony Lembi
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Slipping clutch

#1 Post by Anthony Lembi » Sun Jan 14, 2018 4:07 pm

This is a 60 T5B that sat for over 30 years. I don’t know the history of the clutch and bearing. The car started up and seems to run and shift fine but the clutch really slips in third gear. I have only driven it for a couple of blocks. Could rust on the flywheel or pressure plate make it slip? Does this bearing look like a problem? I expected it to be cleaner. Can you tell if it is the original style? Could a main seal leak leave it looking like this? It looks pretty clean behind it and no oil leaking to the ground. It moves easily along the shaft. Also, I cannot move the pivot shaft by hand even with the clutch cable disconnected. There may be just a touch of free play but hardly perceptible if there at all. It does move fine with the pedal and the bearing does not make any noise.

Sorry for all of the questions. I know the photo leaves a lot to be desired but I took it through the inspection hole with an inexpensive boroscope. The clutch is almost fully depressed in this shot. I think it would be best to pull the motor and actually take a look at why it is slipping. There is no way to get it to stop slipping short of getting in there, correct? I just don’t want to remove the motor if it isn’t necessary. Probably best to pull it anyway. Any help would be appreciated.
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C J Murray
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Re: Slipping clutch

#2 Post by C J Murray » Sun Jan 14, 2018 4:27 pm

Make sure there is enough play at the lever on the trans that you can feel the movement...but not much. You can't tell with your foot. If it slips then you need a clutch.
'57 Speedster
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'60 Devin D Porsche Race Car - Finally Finished!
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'67 911 S Original Owner

Anthony Lembi
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Re: Slipping clutch

#3 Post by Anthony Lembi » Sun Jan 14, 2018 6:13 pm

Thank you, I really appreciate your help, that makes sense to me. Would a new thicker clutch plate increase the free play at the lever?

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C J Murray
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Re: Slipping clutch

#4 Post by C J Murray » Sun Jan 14, 2018 6:57 pm

A change to a thicker disc will increase the free-play which will then need to be adjusted down to a small amount again. As a clutch wears the free-play is reduced and if not adjusted the cable may hold the clutch to where it is not fully clamped by the pressure plate.
'57 Speedster
'59 Sunroof
'60 Devin D Porsche Race Car - Finally Finished!
'63 GS 2133 coupe
'64 Elva Courier mk4T
'67 911 S Original Owner

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Jim Liberty
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Re: Slipping clutch

#5 Post by Jim Liberty » Sun Jan 14, 2018 7:48 pm

CJ, if nobody has said "Thank You" for helping out on the Forum, you are hearing it from me. ............Jim.
Jim Liberty

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C J Murray
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Re: Slipping clutch

#6 Post by C J Murray » Sun Jan 14, 2018 8:02 pm

Thank you Jim but there are many others, you included, that do as much. "It takes a village". I can't believe I said that! :P :shock:
'57 Speedster
'59 Sunroof
'60 Devin D Porsche Race Car - Finally Finished!
'63 GS 2133 coupe
'64 Elva Courier mk4T
'67 911 S Original Owner

Erik Thomas
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Re: Slipping clutch

#7 Post by Erik Thomas » Mon Jan 15, 2018 7:43 pm

My T-5 has two means to adjust the clutch cable. The wing nut a the T.O. lever end, and a nut at the clutch pedal end. You can reach that by removing the wood floor board on the drivers side. Make sure all the linkages are clean and lubricated with motor oil. Free play should be as per the owners manual, measured at the clutch pedal. If the car has sat for a long time, the clutch release lever that works the throw out bearing may need some lubrication. Might try to spray the ends of it with Kroil. I like to use Never Seize on the wing nut, if you can get it loose. Some cable lube sprayed into the clutch cable tube is also a fine thing.

Martin Benade
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Re: Slipping clutch

#8 Post by Martin Benade » Mon Jan 15, 2018 11:03 pm

A wing nut is a VW part and the Porsche lever is not shaped to hold it from adjusting itself. You should have a ball-shaped nut and a locknut to hold it in place at the rear.

Geoff Fleming
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Re: Slipping clutch

#9 Post by Geoff Fleming » Mon Jan 15, 2018 11:54 pm

Another cause of a slipping clutch is severe wear on the 'ears' of the throw-out bearing.
Since the car has sat for decades, it may be well worth it to pull the engine, clean/ replace components, etc. Proper lubrication is critical...be sure there is oil in the transmission also. A good winter project would be to systematically clean all electric wire ends, fuses, ground straps, etc. Lubricate the clutch cable and gas pedal mechanism. Clean headlight and all turn signal grounds...remove/ replace old battery ground strap with new one and carefully clean the area where it attaches to the chassis. Cut back the main battery cable an inch or so, if you don't see clean copper. You will be rewarded with a car that is dependable and reliable with bright lights, etc. ( and a properly functioning clutch!)

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Wil Mittelbach
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Re: Slipping clutch

#10 Post by Wil Mittelbach » Tue Jan 16, 2018 12:01 am

Jim Liberty wrote:CJ, if nobody has said "Thank You" for helping out on the Forum, you are hearing it from me. ............Jim.
++1

Anthony Lembi
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Re: Slipping clutch

#11 Post by Anthony Lembi » Tue Jan 16, 2018 1:43 am

Thanks again. Time to remove the motor. If I find something other than a worn out clutch I will let you know.

I appreciate the help and advise.

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Re: Slipping clutch

#12 Post by Mike Horton » Tue Jan 16, 2018 11:41 am

If it still has the original pressure plate, also check that the diaphragm is not broken at the outer edge of the rim. This can happen if the clutch pedal stop is not adjusted,sand the diaphragm extends over center. It happened to me once, with the Hauserman PP retrofitted into a '57.
Mike

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