Pedal box question regarding the clutch

jonbot · 11-10-2007, 05:22 PM

Today I did a little bit of work on my '79 SC, replaced some fuses, rewired the stereo, minor things. Well, on my way home I pulled up to a stop sign and pushed the clutch in, keep in mind it's cable operated on this car. About 3/4 of the way to the floor I feel a weird pop I haven't felt before in the pedal, and when I let my foot back up off of the clutch, it remained on the floor. I was able to pull the clutch back up to normal position, but it falls back to the floor (Pulled by the helper spring).

I towed the car home and had a look under it. Everything is fine on the transmission end, the problem is in the pedal box. It seems the clutch pedal can move up and down, but the "transfer shaft" in the base of the pedal box does not move. Is there a roll pin or something that connects the pedal to the shaft?

I'm going to remove the pedal box tomorrow to have a closer look, looks pretty easy to remove, only 4 bolts. I just thought I'd run it by you guys first, seeing as how my Bentley book isn't here yet. This type of thing doesn't surprise me on a 30 year old car, I'm just happy it wasn't anything major.

Jon

Jim727 · 11-10-2007, 05:31 PM

One thing to definitely check is the clevis and pin which connects the end of the clutch cable to the base of the pedal. There was another discussion of this in the last few days, I think, but the clevis does have a habit of failing at inopportune times. Mine has broken a couple of times - enough so that I carry a spare in the car. Not too difficult to replace, just difficult to reach.

Porsche-poor · 11-10-2007, 05:44 PM

Yes there is a roll pin that goes through the clutch pedal and the main shaft of the assembly. They do tend to break. Also keep in mind its four bolts, two under the car and two inside but there is also the rod and the brace that run up to the brake booster. A good while your in there would be to inspect the bushings and replace them if they are the plastic ones.

jonbot · 11-10-2007, 06:21 PM

Quote:

Originally Posted by Porsche-poor

A good while your in there would be to inspect the bushings and replace them if they are the plastic ones.

Okay, will do that, thank you

Jon

jonbot · 07:01 PM

Thank you Porsche-poor and Jim727 for the help on this, this was an easier job knowing what to expect. In total, this was a 2 1/2 hour job.

After pulling the pedal assembly out of the car and inspecting it, the problem did turn out to be a sheared roll-pin. After the repair, the clutch works great, although it is now out of adjustment. This was to be expected, as I'm sure the pin had been failing for some time, and the problem slowly manifested itself as a mis-adjusted clutch, so the clutch was re-adjusted at the time.

I took some pics that are useful in diagnosing whether or not you may have a sheared roll-pin in their clutch pedal.

It is rather hard to see in the pictures, because it's tucked behind the center tunnel, but if you focus on the area I've highlighted you can see part of the lever that is attached to the transfer shaft, this is the lever that actually pulls on the clutch cable. Notice in both pictures, whether the pedal is all the way up, or all the way down, the silver lever stays in the same position.

Pedal up:

Pedal down:

Hope this saves someone some time and money in the future in diagnosing their problem.

Jon