1982 sc severe clutch judder

[kodioneill]

i just bought a used 1982 911sc nice shape. engine runs like new. occasionally when starting out the clutch judder so bad it feels like the car is jumping up and down and stalls . then you can start and stop 20 times without it happening. the previous owner had the clutch replaced 15,000 miles ago. even though that means nothing. has there been problems like this with the sc? my 74 never does this. it is dangerous. could it be the dreaded rubber center disc?

[calling911]

Originally Posted by kodioneill

i just bought a used 1982 911sc nice shape. engine runs like new. occasionally when starting out the clutch judder so bad it feels like the car is jumping up and down and stalls . then you can start and stop 20 times without it happening. the previous owner had the clutch replaced 15,000 miles ago. even though that means nothing. has there been problems like this with the sc? my 74 never does this. it is dangerous. could it be the dreaded rubber center disc?

Rear seal leak.. pull the engine, replace it and reinstall. Problem solved.

Actually I have no idea.. if it were a chevy this would be my thought.

[Superman]

Check the four motor mounts. Also check to make sure the clutch cable is properly adjusted. And when the cable is properly adjusted, it "bows" up and over the throttle linkage. If it is touching the throttle linkage, you might have real trouble operating one or both.

[kodioneill]

Originally Posted by calling911

Rear seal leak.. pull the engine, replace it and reinstall. Problem solved.

Actually I have no idea.. if it were a chevy this would be my thought.

no oil leaking !

[robert walsh]

Replace the cable. adjust, pitha, it will all be fine.

[kodioneill]

Originally Posted by Superman

Check the four motor mounts. Also check to make sure the clutch cable is properly adjusted. And when the cable is properly adjusted, it "bows" up and over the throttle linkage. If it is touching the throttle linkage, you might have real trouble operating one or both.

what do you mean "bows" up and over? do you mean the area near the pedal cluster? some clown may have replaced the cable in the past.

[Superman]

No. Aside the transmission. There is a stud that pokes out of the transmission and a metal thingie that swings on that stud. This is part of the throttle linkage. There are throttle shafts that connect to this thingie. One coming rearward from the tub tunnel, and one continuing rearward and upward to the engine. The clutch cable sheath goes up and over these moving parts. It bows under a bit of pressure. Bows upward, away from contacting the thingie. It might be called a Bowden Tube. At any rate, if this Bowden Tube were in contact with the throttle linkage, then a small bit of clutch chatter would be oscillating your throttle linkage. Voila.....massive clutch chatter.

[kodioneill]

Originally Posted by Superman

No. Aside the transmission. There is a stud that pokes out of the transmission and a metal thingie that swings on that stud. This is part of the throttle linkage. There are throttle shafts that connect to this thingie. One coming rearward from the tub tunnel, and one continuing rearward and upward to the engine. The clutch cable sheath goes up and over these moving parts. It bows under a bit of pressure. Bows upward, away from contacting the thingie. It might be called a Bowden Tube. At any rate, if this Bowden Tube were in contact with the throttle linkage, then a small bit of clutch chatter would be oscillating your throttle linkage. Voila.....massive clutch chatter.

i love thingie. i will check the pivot tomorrow.
thanks

[flatsixnut]

If you are going to mess around with the clutch cable, you might as well pull it all the way out and inspect it for wear. Easy enough DIY. If it does need replacing make sure to use OEM and not aftermarket cable. OEM cable will run you about $80. Do not skimp here.

[84CarreraSC]

Mine did the same thing right up till the clutch fell apart. When I pulled the motor the throwout bearing was in pieces.

[72 four door]

could be a warped flywheel wonder if it was cut when the clutch was replaced. did anyone do a burn out recently? maybe a glazed clutch.i don't think this is an adjustment issue,if its shuddering its in the disc or flywheel.

[kodioneill]

thank you all for your input.
i have to wonder why it is an intermittent problem. by that i mean, you can start and stop in first gear 20 maybe 30 times in a row then the judder comes one time. there are times you can drive all day with out a problem!! i had wondered if to much crankshaft end play could cause this problem to reacure under a high torque condition.
well, tomorrow i will check all these components. except the actual clutch.

does anyone know when they stopped using the rubber centered clutch disc???

[DCred911SC]

Mine did that. It was the clutch release fork. They're prone to cracking at the base of the legs, and over time they start to bend resulting in one leg moving out of alignment with the other. If you have to go in to check the clutch, it would be worthwhile checking it out.

David

[kodioneill]

THANKS EVERYONE. put car on lift this am, helper spring ok. as superman stated in an earlier reply, the cable should "bow" over the throttle linkage pivot. the cable was bound up against the tube and was worn down almost through the metal clad sheath. also upon further close inspection i noticed some collapsing of the cable housing at the firewall. cable on order. not to say that this is the final repair but the process has begun.

[Paulporsche]

kodioneill,

The word is that the rubber center of that clutch, which gave a smoother, dampened feel when new, would often disintegrate violently when @ the end if its life, causing further damage to the whole assembly.

[kodioneill]

Originally Posted by Paulporsche

kodioneill,

The word is that the rubber center of that clutch, which gave a smoother, dampened feel when new, would often disintegrate violently when @ the end if its life, causing further damage to the whole assembly.

i was wondering when porsche stopped installing these discs.