clutch help spring missing

[dave123456789]

Hi all,

my car is missing this spring and also the part of the gearbox it mounts to.

first question is would this cause a heavy clutch pedal? im unsure if clutch is supposed to feel like it does now which is heavy. I got a new horse shoe spring on and clutch cable but only recently noticed thats springs missing. likely since i got it sincehavent had it long.

second question as the mount point is gone would i be safe to drill and tap that bit with say a M8 or M10 size bit and put a bolt in there? would this leak oil?

thanks all.

see poorly edited picture below to show what im talking about.

[Dpmulvan]

Yes to your first question. You can add bolt it won’t leak, just do a good job use a drill press or milling machine and a quality tap.

[75 911s]

What year is your car?

[dave123456789]

Originally Posted by Dpmulvan

Yes to your first question. You can add bolt it won’t leak, just do a good job use a drill press or milling machine and a quality tap.

Thank you for your response. I’m going to drill it out while everything is still in the car there’s plenty room under there to not have to remove gearbox.

[dave123456789]

Originally Posted by 75 911s

what year is your car?

1982 sc

[Walt Fricke]

I don't think the absence of this spring will cause a heavy pedal. I think it is there to hold the clutch fork against the throw out bearing so its outer part, which sits on the transmission guide tube, doesn't rotate as much. The guide tube is not meant to be a surface around which something constantly rotates. Neither is the slot in the TOB meant to be constantly rotating against the ends of the shift fork.

The most common causes of a hard clutch, after problems with the harp spring, are issues with the cable (easy to deal with by replacing the cable, and having the vertical shaft in the transmission get sticky on its bushings (have to remove at least the engine).

But you should do your bolt thing, or some substitute. Plenty of meat in that flange on the bottom of the transmission. You can tell just by looking how far in the upward direction the inner surface of the differential housing is. If you do as you propose, you might consider cutting the head off the bolt, as getting the spring on can call for use of a fair amount of force, and you don't need the bolt head as a lip to hold it on.

[Kraftwerk]

After tapping that area I would leave the bolt-head on so the spring doesn't slide off (again?) I actually put a little hose clamp on the end there for that purpose. But that said, Walt Fricke has been at this a lot longer than I have and is probably right !

[dave123456789]

Originally Posted by Walt Fricke

I don't think the absence of this spring will cause a heavy pedal. I think it is there to hold the clutch fork against the throw out bearing so its outer part, which sits on the transmission guide tube, doesn't rotate as much. The guide tube is not meant to be a surface around which something constantly rotates. Neither is the slot in the TOB meant to be constantly rotating against the ends of the shift fork.

The most common causes of a hard clutch, after problems with the harp spring, are issues with the cable (easy to deal with by replacing the cable, and having the vertical shaft in the transmission get sticky on its bushings (have to remove at least the engine).

But you should do your bolt thing, or some substitute. Plenty of meat in that flange on the bottom of the transmission. You can tell just by looking how far in the upward direction the inner surface of the differential housing is. If you do as you propose, you might consider cutting the head off the bolt, as getting the spring on can call for use of a fair amount of force, and you don't need the bolt head as a lip to hold it on.

I have done the horse shoe spring and the clutch cable. Clutch is ok enough to live with but certain isn’t a pleasure to drive. Unsure what else it can be except that missing spring. I though as it’s pulling against that arm it also assist the clutch in a way?

[dave123456789]

With more investigation I found out my pedal was not doing what was expected when I replaced the clutch cable. I could lift it up with my hand and didn’t need to use a chock to hold it up while installing the cable. Bit suspicious.

Turns out the clutch spring pedal end is also missing. Here’s hoping when all these springs I’ve order arrive this pedal will be as light. I also ordered pedal box bushing kit and will service that as well

[Walt Fricke]

Porsche felt a cylindrical casting was good enough to hold that spring in place. It is a pretty stiff little bugger, so the easier it is to get on or off, the better. I've never had mine slide off all on its own - the angle holds it on nicely.

Another reason I don't think it contributes significantly to reducing the pressure needed by your foot on the pedal is the geometry: this spring acts on a very short lever arm. The harp and the cable act on a whole lot longer arm. The harp is especially clever, since you don't want to be reducing the actual clamping force of the clutch diaphragm spring while you are driving.