Clutch problem is it normal?

[John_in_nc]

I just got my 81 911SC a few weeks ago. I am having a very hard time driving it. The clutch engages pretty much all at once without much warning. I kill it out of 1st gear about once out of every 10 tries. I think part of the problem is the clutch pedal doesn't come up smoothly. It feels like it is rubbing somewhere down inside. So it comes up more in spurts than a fluid motion. That makes is more luck than anything else for a smooth start.

I took it to a local shop that has worked on this particular car for years (for the previous owner). They are telling me it's normal. If this is normal I'm selling this car, I just get angry and stressed every time I drive it. It's either I kill it trying to be smooth, or I damn near rear end the car in front of me when the light turns green.

[wwest]

'81.....You may have rubber center clutch that is coming apart.

Helper spring may have popped off.

[jimrs2000]

Check the cable, had the same problem a few weeks ago.....that is until the cable broke!!

[jmohn]

While you may have an issue, I think it's more likely you're just not used to the non-linear feel of the clutch pedal movement. This is due to the "helper" spring which reduces pedal effort at approximately the half-way point in the pedal travel. You just need to get comfortable with the "feel" of the pedal travel and anticipate when the pedal feel comes "over center", and not allow the return to overcome your leg effort.

I've driven a lot of differing vehicles (including some older heavy equipment with REALLY heavy clutch effort) but it took awhile to get familiar with the non-linear feel of my SC's clutch pedal.

Jerry M
'78 SC

[euro911sc]

@Jmohn: Hunh? I never thought the clutch on my 911 was non-linear... I'll have to check.

My clutch is smooth and easy to modulate. Very easy. Something is amiss with your car. You may want to have another Porsche guy drive it around the block. Maybe there is another Pelican near you? Then they can tell you its you or its the car.

I had a similar issue, but it was every time and it took the wrench 6 months to fix it. The Throwout bearing was getting stuck on the guide tube. So when I let out my foot the bearing would stick then unstick and effectively drop the clutch. Not very pleasant. Yours could be in an early state like this. Fix requires that the trans be pulled out and the guide tube replaced. Probably good to replace the throwout bearing too. You can also check the clutch condition at this time as well.

If your cable is old it is also a good time to do that too and its not that expensive.

perhaps the cable needs adjusting also?

-Michael

[John_in_nc]

I took it to get adjusted, it didn't help. I think I'll just start taking things apart until I get it figured out.

I live in Raleigh, NC

[Techne]

It could be something in the pedal assembly too. They can get rusty, the bushings get old and fail, which would make the pedal bind or not move smoothly.

[john walker's workshop]

a clutch cable that has a broken and bunched up inner sheath can feel notchy and wierd. a gear oil soaked clutch disc is usually grabby. you can have the horseshoe spring removed to get rid of that "pop up" feeling.

[John_in_nc]

Ok I have been trouble shooting this all evening. Thanks so much for the awesome response here!

I traced the binding to the clutch cable. The pedal assembly looks good. I have paperwork that shows the clutch cable being replaced last year. It looks new. I was able to almost eliminate the binding by pulling down on the clutch cable down by the clutch while my wife pushed the pedal in and out.

Should the clutch cable run above or below the throttle bell crank? Maybe it was ran wrong? Right now it goes above the throttle bell crank before going into the body.

So should it look like this picture: http://www.pelicanparts.com/techarticles/911_clutch_replace/pic35.JPG

or this picture:
http://www.pelicanparts.com/techarticles/911_clutch_replace/pic22.JPG

Also, I hate the way the pedal feels. Somebody mentioned removing the "horseshoe" spring. Is there after market clutch springs that give a more even clutch release feel?

[pete3799]

The second picture is correct.

[Roby466]

I would not remove the helper spring... I just installed it properly on my friend's 77 911 and he felt like I gave him a new car. The spring when adjusted properly makes the pedal a LOT more civilized. It is something that was added by Porsche just before 77 to remedy to a too heavy clutch pedal.
Make sure that the adjustment is done properly according to spec (1.2mm without the cable attached down to 1mm play with the cable adjusted properly) and that the stops at the pedal have been set properly both on the floor and on the floor plate. I think that you are supposed to have 25.4mm of travel all this is measured as per Wayne's 101 projects for your 911. Also, make sure that the spring is installed the proper way... I have seen the spring installed the wrong way (by a Porsche shop) and it made the clutch horrible.
Good luck!
Once everything is adjusted properly, it should be relatively easy to push down but it will definitely have the snappy feel that others have described...

[Flat6pac]

If youre close to Rocky Mount, Raleigh, I ll look at the car.. possibly the idle arm is frozen to the vertical shaft, making things very difficult.
Bruce

[JJ 911SC]

Originally Posted by Roby466

... I have seen the spring installed the wrong way (by a Porsche shop) and it made the clutch horrible...

AKA future investment for the shop...

[pete3799]

Originally Posted by Flat6pac

If youre close to Rocky Mount, Raleigh, I ll look at the car.. possibly the idle arm is frozen to the vertical shaft, making things very difficult.
Bruce

This^

[DRACO A5OG]

Originally Posted by Flat6pac

If youre close to Rocky Mount, Raleigh, I ll look at the car.. possibly the idle arm is frozen to the vertical shaft, making things very difficult.
Bruce

+2,

First fire that wrench. That is not the way it is supposed to be. Clutch is supposed to engage halfway up the pedal travel. I recently helped adjust a buddy of mine's to keep him from grinding into gears.

If you want to diagnose this yourself, get a helper to press the clutch while you are safely under the car. Check the movement, if binding then it may be the Helper Arm binding on the shaft as described above. GOING THRU PUDDLES OF WATER IN AND ENGINE CLEANINGS WILL DO THIS, ask me how I know

If you want to fix it: Get a circlip tool to remove circlip on the small arm, use a needle nose to remove spring. Remove small arm ( take note of it's position). Get a BFS and pry the Helper Arm forward, don't worry you will not harm your baby. The Helper Arm should drop down, if not then it is rusted and you may need to use a mallet and BFS to make it release. Shoot some PBBlaster up it if need. Depending on your year there should be two dust covers, one in front and behind the arm.

Once removed, remove all corrosion and rust. Lube shaft with MOLY Grease or Bearing Grease. Replace the dust cover if still good, if not you will need to order new ones, they should be soft not hard an brittle. I placed some lube on them to help seal the shaft from the elements.

Replace in Reverse. Do not worry, there is no adjustments needed, if you are anal you can check but if you replace as you found it all readings will be the same.

If clutch is still engaging too low then you need to adjust the cable. if the adjustment nut is at it's end then your cable is stretched and you will need a new cable. Remember with the helper, the difference between depressed and pressed clutch must be 25.0MM (=/- 0.5 MM) per SPEC. If done correctly, your pedal height will be the same as your Brake pedal. Ask your help how the pedal height is during the adjustment.

Don't let this intimidate you, you can do this yourself and fire the wrench.

Jim

PM me if you want more details

[jimrs2000]

Removing the clutch cable is quick and easy, the entire change took me less than an hour after the old one snapped.

I would disconnect it at both ends and see if it moves smoothly, mine had frayed and was binding in the outer giving exactly the problem you describe.

Changing it has transformed the car for me, very smooth and easy to operate now.

[DRACO A5OG]

Originally Posted by jimrs2000

Removing the clutch cable is quick and easy, the entire change took me less than an hour after the old one snapped.

I would disconnect it at both ends and see if it moves smoothly, mine had frayed and was binding in the outer giving exactly the problem you describe.

Changing it has transformed the car for me, very smooth and easy to operate now.

Another Great TIP! Isolate the components to verify a failed unit.